1. Florence, Ronald (1994). The Perfect Machine. New York: HarperCollins. (Hale’s role in the conception and building of the Yerkes, Mount Wilson, and Palomar telescopes.)
2. Kevles, Daniel J. (1968). “George Ellery Hale, the First World War, and the Advancement of Science in America.” Isis 59: 427–437.
3. Osterbrock, Donald E. (1993). Pauper and Prince: Ritchey, Hale, and Big American Telescopes. Tucson: University of Arizona Press.
4. — (1995). Founded in 1895 by George E. Hale and James E. Keeler: The Astrophysical Journal Centennial. Astrophysical Journal 438: 1–7.
5. — (1997). Yerkes Observatory, 1892–1950: The Birth, Near Death, and Resurrection of a Scientific Research Institution. Chicago: University of Chicago Press.