added video links

docs/en/Best-Practices/Application-Services.md

@@ -228,4 +228,9 @@ This method votes a question and returns the current score of the question.
   * The current module has only reference to the application contracts of the used module.
 
 
+## See Also
+
+* [Video tutorial Part-1](https://abp.io/video-courses/essentials/application-services-part-1)
+* [Video tutorial Part-2](https://abp.io/video-courses/essentials/application-services-part-2)
+
 

docs/en/Best-Practices/Data-Transfer-Objects.md

@@ -6,4 +6,8 @@
 * **Do** define DTO members with **public getter and setter**.
 * **Do** use **data annotations** for **validation** on the properties of DTOs those are inputs of the service.
 * **Do** not add any **logic** into DTOs except implementing `IValidatableObject` when necessary.
-* **Do** mark all DTOs as **[Serializable]** since they are already serializable and developers may want to binary serialize them.
+* **Do** mark all DTOs as **[Serializable]** since they are already serializable and developers may want to binary serialize them.
+
+## See Also
+
+* [Video tutorial](https://abp.io/video-courses/essentials/data-transfer-objects)

docs/en/Best-Practices/Domain-Services.md

@@ -2,3 +2,6 @@
 
 > **This document is not ready yet. Please see the [Domain Services](../Domain-Services.md) document.**
 
+## See Also
+
+* [Video tutorial](https://abp.io/video-courses/essentials/domain-services)

docs/en/Best-Practices/Entities.md

@@ -154,4 +154,8 @@ public class IssueLabel : Entity
 ### References
 
 * Effective Aggregate Design by Vaughn Vernon
-  http://dddcommunity.org/library/vernon_2011
+  http://dddcommunity.org/library/vernon_2011
+
+  ## See Also
+
+* [Video tutorial](https://abp.io/video-courses/essentials/entities)

docs/en/Best-Practices/Repositories.md

@@ -72,3 +72,4 @@ Task<List<IdentityUser>> GetListByNormalizedRoleNameAsync(
 
 * [Entity Framework Core Integration](Entity-Framework-Core-Integration.md)
 * [MongoDB Integration](MongoDB-Integration.md)
+* [Video tutorial](https://abp.io/video-courses/essentials/app-template)