Donald E. Osterbrock, James E. Keeler: Pioneer American Astrophysicist and Early Development of American AstrophysicsDOI: info:10.1177/002182868701800216v. 18No. 2141–142
Kidwell, Peggy Aldrich. 1987. [Book review] "Donald E. Osterbrock, James E. Keeler: Pioneer American Astrophysicist and Early Development of American Astrophysics." Journal for History of Astronomy, 18, (2), 141–142. https://doi.org/10.1177/002182868701800216.