https://digital.scetv.org/knowitall/nasa/invention_process/timeline.html
https://www.factmonster.com/science/inventions/timeline-everyday-inventions
http://inventors.about.com/od/timelines/a/twentieth.htm
http://encyclopedia.kids.net.au/page/ti/Timeline_of_invention#Significant_modern_inventions,_arranged_in_chronological_order