Letter (paper size) - Wikipedia

Half Letter Size Paper – Great for Business Documents, Letters, Arts, Prints and Crafts, Copy, Printing, Writing, 8.5” x 5.5”, 20lb White Bond Paper

Book size - Wikipedia

Paper Size - Wikipedia, PDF, Printing Materials

US Paper Sizes Letter, Legal, Tabloid, Ledger, Junior Legal, Half Letter, Government Letter, Government Legal, ANSI A, ANSI B

Display aspect ratio - Wikipedia

Paperboard - Wikipedia

ISO 216 - Wikipedia

Tabloid (newspaper format) - Wikipedia

Foolscap folio - Wikipedia