Yodiz now offers more smoother way to associate user stories to issues and vice versa. You can even create the “Association” link between items from different projects. Association relation is part of “Dependencies” functionality that is recently introduced. Besides “Association” you can create other hard dependencies like “Is Blocked by” and “Blocked By”.For more details check this help article.
To view dependencies at Item detail view click on “Dependencies” option as shown in.