Adding a footnote citation for a reference with several volumes is difficult. you you have a book for a example that has several volumes, and you are adding a citation to a specific volume, after pressing Ctrl+Alt+P and looking for the specific book, you can’t tell which volume you are picking. there has to be a way to figure out which volume you are choosing.
Thanks for your feedback on adding these types of citations, @Fr_David_Elias. I’ve added your request to our internal feature tracker as a usability improvement for consideration in the future.