Returning to Chicago, where his studies were supervised by Bliss, he completed work on his thesis and he was awarded his PhD in 1930.
Bumabalik sa Chicago, kung saan ang kanyang pag-aaral ay supervised sa pamamagitan ng lubos na kaligayahan, siya natapos ng trabaho sa kanyang tesis at siya ay iginawad sa kanyang PhD sa 1930.