diff --git a/README.md b/README.md
index 3cb318c5f241..279e9e907862 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@
 * a collection of native C++ classes libraries, to **extend** std;
 * API close to the .net API with a modern C++ approach and full integration with the std standard;
 * xtd is designed to manage GUI controls and dialogs in pure [native mode](https://gammasoft71.github.io/xtd/docs/documentation/Guides/xtd.forms/Overview/control_appearance) or with [CSS styles](https://gammasoft71.github.io/xtd/docs/documentation/Guides/xtd.forms/Style%20sheets/style_sheets_overview).
-* written in efficient, modern [C++17/20](https://en.cppreference.com/w/) with [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom;
+* written in efficient, modern [C++17/20](https://en.cppreference.com/w/) with [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom;
 * and [highly portable](https://gammasoft71.github.io/xtd/docs/documentation/portability) and available on [many different platforms](https://gammasoft71.github.io/xtd/docs/documentation/portability);
 * See [features](https://gammasoft71.github.io/xtd/docs/documentation/features) for more informations.
 
diff --git a/docs/controls_management.md b/docs/controls_management.md
index 80a881d508fa..afd7a17046cf 100644
--- a/docs/controls_management.md
+++ b/docs/controls_management.md
@@ -10,7 +10,7 @@
 
 * The [xtd.forms](https://gammasoft71.github.io/xtd/reference_guides/latest/group__xtd__forms.html) library does not manage memory for you.
   
-  Each control manages its own resources on the [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom. And it does not manage your objects.
+  Each control manages its own resources on the [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom. And it does not manage your objects.
 
 * A control can be created on the stack or dynamically in the heap.
   
@@ -210,7 +210,7 @@ auto main() -> int {
 }
 ```
 
-In addition, you will respect the [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom.
+In addition, you will respect the [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom.
 
 # Close form
 
diff --git a/docs/doxygen/doxygen/main_page.dox b/docs/doxygen/doxygen/main_page.dox
index 817ad83e8941..f509dfe96728 100644
--- a/docs/doxygen/doxygen/main_page.dox
+++ b/docs/doxygen/doxygen/main_page.dox
@@ -12,7 +12,7 @@
 ///   * a collection of native C++ classes libraries, to complete std;
 ///   * API close to the .net API with a modern C++ approach and full integration with the std standard;
 ///   * xtd is designed to manage GUI controls and dialogs in pure [native mode](https://gammasoft71.github.io/xtd/docs/documentation/Guides/xtd.forms/Overview/control_appearance) or with [CSS styles](https://gammasoft71.github.io/xtd/docs/documentation/Guides/xtd.forms/Style%20sheets/style_sheets_overview).
-///   * written in efficient, modern [C++ 17/20](https://en.cppreference.com/w/) with [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom;
+///   * written in efficient, modern [C++ 17/20](https://en.cppreference.com/w/) with [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom;
 ///   * and [highly](https://gammasoft71.github.io/xtd/docs/documentation/portability) portable and available on [many different platforms](https://gammasoft71.github.io/xtd/docs/documentation/portability) (Windows, macOS, Linux, iOS and android);
 ///   * See [features](https://gammasoft71.github.io/xtd/docs/documentation/features) for more informations.
 ///
diff --git a/docs/doxygen/doxygen_developer/main_page.dox b/docs/doxygen/doxygen_developer/main_page.dox
index 4d47d2d7cec2..b1cb191fd53e 100644
--- a/docs/doxygen/doxygen_developer/main_page.dox
+++ b/docs/doxygen/doxygen_developer/main_page.dox
@@ -12,7 +12,7 @@
 ///   * a collection of native C++ classes libraries, to complete std;
 ///   * API close to the .net API with a modern C++ approach and full integration with the std standard;
 ///   * xtd is designed to manage GUI controls and dialogs in pure [native mode](https://gammasoft71.github.io/xtd/docs/documentation/Guides/xtd.forms/Overview/control_appearance) or with [CSS styles](https://gammasoft71.github.io/xtd/docs/documentation/Guides/xtd.forms/Style%20sheets/style_sheets_overview).
-///   * written in efficient, modern [C++ 17/20](https://en.cppreference.com/w/) with [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom;
+///   * written in efficient, modern [C++ 17/20](https://en.cppreference.com/w/) with [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom;
 ///   * and [highly](https://gammasoft71.github.io/xtd/docs/documentation/portability) portable and available on [many different platforms](https://gammasoft71.github.io/xtd/docs/documentation/portability) (Windows, macOS, Linux, iOS and android);
 ///   * See [features](https://gammasoft71.github.io/xtd/docs/documentation/features) for more informations.
 ///
diff --git a/docs/home.md b/docs/home.md
index e7b8b6357698..a77616c65c3e 100644
--- a/docs/home.md
+++ b/docs/home.md
@@ -15,7 +15,7 @@
 * Free and open-source ([MIT License](https://github.com/gammasoft71/xtd/blob/master/docs/license.md));
 * a collection of native C++ classes libraries, to complete std;
 * API close to the .net API with a modern C++ approach and full integration with the std standard;
-* written in efficient, modern C++17/20 with [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom;
+* written in efficient, modern C++17/20 with [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom;
 * and [highly portable](portability.md#the-xtd-libraries-portability-list) and available on [many different platforms](portability.md#operating-system-supported);
 
 ## xtd libraries architecture
diff --git a/docs/introduction_to_xtd.md b/docs/introduction_to_xtd.md
index 5ee9304b3730..8861d031c993 100644
--- a/docs/introduction_to_xtd.md
+++ b/docs/introduction_to_xtd.md
@@ -18,7 +18,7 @@
 * a collection of native C++ classes libraries, to **extend** std;
 * API close to the .net API with a modern C++ approach and full integration with the std standard;
 * `xtd` is designed to manage GUI controls and dialogs in pure [native mode](https://github.com/gammasoft71/xtd/blob/master/docs/control_appearance.md) or with [CSS styles](https://github.com/gammasoft71/xtd/blob/master/docs/style_sheets_overview.md).
-* written in efficient, modern C++17 / C++20 with [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom;
+* written in efficient, modern C++17 / C++20 with [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom;
 * and [highly portable](https://gammasoft71.github.io/xtd/docs/documentation/portability) and available on [many different platforms](https://gammasoft71.github.io/xtd/docs/documentation/portability);
 
 ## Using xtd
diff --git a/docs/xtd_explanations.md b/docs/xtd_explanations.md
index 6a15d120f887..97c9b9ff8098 100644
--- a/docs/xtd_explanations.md
+++ b/docs/xtd_explanations.md
@@ -46,7 +46,7 @@
 What are the criteria for a modern C++ framework in 2019 :
 
 * C++17/20 modern
-* [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) programming idiom.
+* [RAII](https://en.cppreference.com/w/cpp/language/raii) programming idiom.
 * Use of namespace and no prefix
 * No defines for constants and no macros for functions or event logging.
 * All classes must be in namespaces.
diff --git a/src/xtd.core/include/xtd/scope_exit.hpp b/src/xtd.core/include/xtd/scope_exit.hpp
index 9e014950159d..b46fbc3de00a 100644
--- a/src/xtd.core/include/xtd/scope_exit.hpp
+++ b/src/xtd.core/include/xtd/scope_exit.hpp
@@ -6,14 +6,14 @@
 
 /// @brief The xtd namespace contains all fundamental classes to access Hardware, Os, System, and more.
 namespace xtd {
-  /// @brief Nowadays, every C++ developer is familiar with the Resource Acquisition Is Initialization ([RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization)) technique. It binds resource acquisition and release to initialization and destruction of a variable that holds the resource. There are times when writing a special class for such a variable is not worth the effort. This is when xtd xtd::scope_exit comes into play.
+  /// @brief Nowadays, every C++ developer is familiar with the Resource Acquisition Is Initialization ([RAII](https://en.cppreference.com/w/cpp/language/raii)) technique. It binds resource acquisition and release to initialization and destruction of a variable that holds the resource. There are times when writing a special class for such a variable is not worth the effort. This is when xtd xtd::scope_exit comes into play.
   /// @par Namespace
   /// xtd
   /// @par Library
   /// xtd.core
   /// @ingroup xtd_core
   /// @remarks See also #scope_exit_ keyword helper.
-  /// @warning Prefer use [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) then xtd::scope_exit.
+  /// @warning Prefer use [RAII](https://en.cppreference.com/w/cpp/language/raii) then xtd::scope_exit.
   ///
   /// ```cpp
   /// #include <xtd/xtd>
@@ -64,14 +64,14 @@ namespace xtd {
 #define __xtd_scope_exit_id__(name, line) __xtd_scope_exit_cat__(name, line)
 /// @endcond
 
-/// @brief Nowadays, every C++ developer is familiar with the Resource Acquisition Is Initialization ([RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization)) technique. It binds resource acquisition and release to initialization and destruction of a variable that holds the resource. There are times when writing a special class for such a variable is not worth the effort. This is when xtd #scope_exit_ comes into play.
+/// @brief Nowadays, every C++ developer is familiar with the Resource Acquisition Is Initialization ([RAII](https://en.cppreference.com/w/cpp/language/raii)) technique. It binds resource acquisition and release to initialization and destruction of a variable that holds the resource. There are times when writing a special class for such a variable is not worth the effort. This is when xtd #scope_exit_ comes into play.
 /// @par Namespace
 /// xtd
 /// @par Library
 /// xtd.core
 /// @ingroup xtd_core keywords
 /// @remarks See also xtd::scope_exit struct.
-/// @warning Prefer use [RAII](https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization) then #scope_exit_.
+/// @warning Prefer use [RAII](https://en.cppreference.com/w/cpp/language/raii) then #scope_exit_.
 ///
 /// ```cpp
 /// #include <xtd/xtd>