Four Pogman Books (Books, 1995)

Merch of the foremost brand of collectible cardboard milkcaps. You can digitally borrow them here.

I previously posted about the Internet Archive's milkcap scan collection here.

The Milkcap Stack: The Internet Archive's Milkcap/Pog Collection (Images, various companies, ~1993-~1998)

Hundreds and hundreds of the collectible little cardboard discs - most famously Pogs - from the mid-90's fad. You can view the collection here.