http://www.cracked.com/photoplasty_644_19-cool-design-features-hidden-stuff-you-use-every-day/
http://thechive.com/2014/06/23/40-facts-that-will-change-the-way-you-look-at-everyday-objects-40-photos/
https://www.scoopwhoop.com/blue-part-of-the-eraser/#.pazqrj4k1
http://www.slate.com/articles/life/design/2012/09/can_tabs_how_aluminum_pop_tabs_were_redesigned_to_make_drinking_soda_safer_and_the_world_a_cleaner_place_.html
http://www.sciencealert.com/here-s-why-there-are-holes-in-the-tops-of-pen-caps
http://www.cracked.com/photoplasty_557_26-mind-blowing-true-facts-about-everyday-products/
http://lifehacker.com/5979822/unfold-a-chinese-takeout-box-into-an-emergency-plate
http://www.simplemost.com/sneaky-reason-tic-tacs-can-say-sugar-free-really-arent/
https://brokensecrets.com/2011/05/04/the-signature-line-on-checks-is-not-a-line-at-all/
https://en.wikipedia.org/wiki/Charlemagne
http://www.lifebuzz.com/shirt-loop/
http://www.iflscience.com/physics/what-little-hole-airplane-windows/
http://www.lbc.co.uk/radio/special-shows/the-mystery-hour/culture/what-is-the-small-pocket-on-jeans-11109/