
Interview on WGN Radio (3 May 2011) http://www.wgnradio.com/shows/johnwilliams/wgnam-john-williams-050311-b,0,7181575.mp3file/.
August 1932 Henry and June
Diary entries (1914 - 1974)
Interview on WGN Radio (3 May 2011) http://www.wgnradio.com/shows/johnwilliams/wgnam-john-williams-050311-b,0,7181575.mp3file/.
Television interview ("On clarity and exact thinking" - available on youtube)
1960s
Source: The Untethered Soul: The Journey Beyond Yourself
Canto I, lines 88–90 (tr. Ciardi).
The Divine Comedy (c. 1308–1321), Paradiso
What Are Masterpieces and Why Are There So Few of Them (1936)