Check at the bottom of the description in this file. That’s an example. 
Hello,
i was reading the “9 Tips for Creating and Maximizing a Steady Income Stream by Selling Stock” and under “Tip 2 – Cross Sell” it says that it is important to link other items on a single item page. Well, i don’t know how to do that because when i upload the file all i have is one text field, nothing more.
Can anyone with more experience explain to me please the system behind this.
Thanks 
Check at the bottom of the description in this file. That’s an example. 