[severos]

I remember reading a research couple years ago about shoulder surfing that used different types of surfaces and magnifiers to 'shoulder surf', however I can't seem to find it now... They showed surfaces like window glass, spoon, coffee cup, etc. that reflect light and how 'good' the magnifiers need to be.
I need this for a presentation, so would be awesome if any of you guys know this research or have other resources on such stuff.

Thanks in advance.