Purcell1984
From Kolesnikov.org
Purcell1984: Purcell Edward M. The Back of the Envelope: Acolumn in the American Journal of Physics.— Jan 1983— July 1984. http://www.vendian.org/envelope/dir0/column_purcell.html https://www.aapt.org/Publications/AJP/Readers/back_of_the_envelope.cfm
Kolesnikov2023p67
Purcell1984: Miscellaneous1 https://www.aapt.org/Publications/ajp-themepdfsandpurcell/April1983-Problem2.pdf
