P. Murdin, Wolf, Charles J E (1827-1918) in Encyclopedia of Astronomy and Astrophysics, Bristol, Institute of Physics Publishing, 2001, DOI: 10.1888/0333750888/4101.
C. S. Beals, On the nature of Wolf-Rayet emission, in Monthly Notices of the Royal Astronomical Society, vol. 90, 1929, pp. 202–212. URL consultato il 5 gennaio 2015.
W. Fleming, E. Pickering, Stars having peculiar spectra, in Annals of the Astronomical Observatory of Harvard College, vol. 56, n. 6, 1912, pp. 165-226. URL consultato il 9 dicembre 2014.
A. Barniske, W.-R. Hamann, G. Gräfener, Wolf-Rayet stars of the carbon sequence, Stellar Evolution at Low Metallicity: Mass Loss, Explosions, Cosmology, Tartu, Estonia, 15-19 agosto 2005, Astronomical Society of Pacific, 2006, pp. 243-244, ISBN978-1-58381-221-1. URL consultato il 13 dicembre 2014.