babson sources
Babson’s gravity essay: https://www.physicsforums.com/insights/wp-content/uploads/2016/04/BabsonGravity-OurEnemy.pdf His Autobiography: https://digitalcollections.babson.edu/digital/collection/rogerbabson/id/21/rec/1 His Account of his Presidential Run: https://babel.hathitrust.org/cgi/pt?id=inu.32000009810195&seq=7 Economy: https://www.federalreservehistory.org/essays/stock-market-crash-of-1929 https://www.forbes.com/sites/petercohan/2019/09/05/90-year-ago-roger-babson-predicted-the-market-crash-what-would-he-say-today/?sh=56124be538d6 Gravity: https://www.gravityresearchfoundation.org/historic https://www.popsci.com/science/article/2011-03/gravitys-sworn-enemy-roger-babson-and-gravity-research-foundation/ http://www.newbostonhistoricalsociety.com/gravity.html#:~:text=Roger%20Babson%20(1875%2D1967),his%20sister%20and%20his%20grandson The Magic Circle: https://pubs.lib.uiowa.edu/annals-of-iowa/article/id/34632/ ...