Evangelizing Outside the Box: Web Standards and Large Companies
(A List Apart: Articles)
Raising the Bar for Mobile Standards
How standards documentation puts UX at the core of mobile application development.
Photographic Print Sizes (Wikipedia)
Standard photographic print sizes are used in photographic printing. Cut sheets of paper meant for printing photographs are commonly sold in these sizes.
Paper Sizes (Wikipedia)
There have been many standard sizes of paper at different times and in different countries, but today there are two widespread systems in use: the international standard (A4 and its siblings) and the North American sizes.