Joins in Entity Framework.

There are a lot of article including msdn and a lot more on every place.

The best on which I liked personally are belows:

1. MSDN (https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/ef/language-reference/method-based-query-syntax-examples-join-operators)
2. Kudvekat (https://www.youtube.com/playlist?list=PL4iLdIOlUy5IuGnp7NRdKHlB0PHZdS9EE)
3. C sharp corner (https://www.c-sharpcorner.com/UploadFile/ff2f08/sql-join-in-linq-linq-to-entity-linq-to-sql/)

These are the best in my opinion. Please comment and feel free to add more in the comment section.