Books and Proyects are integrated so expenses can be registered on Proyects and be reflected in Books.

I can see in both Books and Proyects that when I register an Expense (Proyect, Amount, Supplier, etc) this information can be seen on both apps.

I need to make a report on Reports that shows how much has been spent per Proyect, but i cant see what ID or data lets me relate both databases, nor can i find a table/s on either of them that has both expense and proyect.

Is the information that relates expenses to proyects accesible through Reports?