1. The Kitt Peak 2.1-meter telescope: An unusually innovative telescope (abstract).;Bulletin of the American Astronomical Society,2009
2. A description of certain galactic nebulosities. II.;Astrophysical Journal,1957
3. George Ellery Hale (1868–1938).;Astrophysical Journal,1938
4. Early days at Mount Wilson.;Publications of the Astronomical Society of the Pacific,1947