I have personally found it is often easier to find things in a physical book. Say I want to look up an equation that I remember learning about from a particular book.
If it was a physical book there is a good chance I will remember a place for the equation, say about 3/4 of the way through the book, near the top of a left hand page and the right had page had a graph showing solutions of the equation.
I can then quickly riffle through the book to find that spot.
With an ebook I get much less sense of place. If what I read on has consistent paging so I've always seen that equation at the same place on the screen I might remember that but not much more. If the "search" function in the reader software isn't good enough to find the equation and I can't think of enough prose that was around it to find it by searching for that it is going to be harder to find than it is in the physical book.
I think the physical books is activating the same mental facilities that are used to organize memories of a physical journey through a space. An ebook doesn't do that for me.