database first - Adding foreign key in visual studio 2012 - Stack Overflow
How to view table foreign keys (FK) in SQL Server with SSMS (4 ways) - SSMS Tutorials
Javarevisited: Difference between Primary key vs Foreign key in table – SQL Tutorial Example
How can I manually create a foreign key? / Vertabelo / Vertabelo SA
How to create a SQL Server foreign key
Setting foreign key in phpMyAdmin - Databases - SitePoint Forums | Web Development & Design Community
database design - MySQL permits setting a foreign key constraint that references only one column of a composite primary key - Database Administrators Stack Exchange