PDF viewer that makes reference checking easy I'm an academic and I read a lot of papers on-screen in pdf format. Scientific papers always have a list of references at the back, and when reading them it's often necessary to check a reference, which means taking a quick look at the list at the end of the paper, and then returning to where I was reading before. Sometimes these pdfs include hyperlinks to the references, but often they don't.

I would like to know if there are any pdf readers available for OS X that have features designed to make this task easy, of quickly navigating to the end of the document and quickly navigating back to exactly where I left off.

I'm not sure exactly what such a feature would be like - I don't want to constrain the question too much in case there's a way of doing it that I haven't thought of - but what I'm imagining is simply that I can have two 'views' into the pdf and a keyboard shortcut to switch between them. Clicking a hyperlink would open it in the other view, so that the keypress would bring you back to where you were. In case there aren't any hyperlinks, I could just keep one view at the reference list and the other one on the page I'm reading, and I could just switch between them as needed.

I've tried using the split-screen feature in Skim, which is better than nothing, but it's still slightly awkward for me. I have quite poor eyesight and tend to read zoomed in quite far, which means I have to keep resizing the lower panel in order to have enough space to read the main text. I also couldn't find a way to open hyperlinks in the other panel, which means I have to scroll around to find references manually, even if the document I'm reading has hyperlinks.
This is not a split screen solution, but an easy keyboard shortcut to switch between end and current view.

Preview

In Preview you can jump back and forward in your "viewing history" with cmd+[ and cmd+]. After switching to the references at the end with end (or fn+→), you can jump back at the exact same view you were before with cmd+[.

Also remember the page number that is seen in Title bar of Preview and use alt + cmd + G to navigate. 

Acrobat Reader

In Acrobat you can do the same and navigate through the page history with cmd+← and cmd+→.