After much searching, I found the exact thing you're looking for, from Carolina Biological Supply. They are made by BelArt (Cat. #44171), and there is a list of suppliers at the BelArt web site, which I found by searching for "BelArt" on the internet.  They are called "ViewPack microscope slide holder, refill set" from Carolina Biological Supply, (cat. # WW-63-4398), and their phone number is 800-334-5551, or fax 800-222-7112. They cost $22.95/set of 10 sheets. Good Luck,
Joyce Kotzuk, UNM pathology.

>>> "Garza-Williams, Sara" <Garza-Williams.Sara@tchden.org> 03/16/00 02:50PM >>>
Can anyone tell me where I can purchase, slide (glass) cover sheets?  They
are simular to the kind you would use for filing kodachromes in a three ring
binder.
But these are made for glass slides.  Hope this makes sense, I'm not sure
what to call them.
Thanks,
Sara Williams