1. Kendall P. M., Warwick the kingmaker (New York, 1957), 12.
2. Wright Helen, Explorer of the universe: A biography of George Ellery Hale (New York, 1966), 28.
3. Osterbrock D. E., Pauper & prince: Ritchey, Hale, & big American telescopes (Tucson, 1993), 23.
4. The varieties of religious experience: A study in human nature.
5. Goodman F. W. and Jamison K. R., Manic-depressive illness (Oxford, 1990), 359.