The history of the paper clip: It was invented in 1899. It hasn't been improved upon since.
Amazon.com : 50 Pack Large Jumbo 4 Inches Long Paper Clips - 100mm Office Supply Paper Clip - Cute Paper Needle - Heavy Duty Bookmark(Black) : Office Products
Paper clips - Etsy France
New Ways to Use Paper Clips — Paper Clip Hacks
Paper Clips - WSC
Otto Paper Clips 100mm Assorted 8 Pack | Officeworks
Paper clip Vectors & Illustrations for Free Download | Freepik
14 Ways to Use Paper Clips - YouTube
Amazon.com : Officemate Premium #1 Paper Clips, 1,000 Paper Clips (10 Boxes of 100 Each) (99916) , Silver : Office Paper Clamps : Office Products
The Paper Clip | Scientific American
Black Blinder Paper Clip, Packaging Size: 12 Piece, for Office