1. George E. Hale (Director), Carnegie Institution of Washington Yearbook, n.16, 1917: Mount Wilson Observatory, (CIWY 1918), pg. 203
2. George E. Hale (Director), Carnegie Institution of Washington Yearbook, n.17, 1918: Mount Wilson Observatory, (CIWY 1919), pg. 217
3. Ibid. pg. 198
4. Interview with Ann Humason Bernt, 2006, from family archive
5. George E. Hale (Director), Carnegie Institution of Washington Yearbook, n.16, 1917: Mount Wilson Observatory, (CIWY 1918), pg. 203