Kellermann, K. I.; Kovalev, Y. Y.; Lister, M. L.; Homan, D. C.; Kadler, M.; Cohen, M. H.; Ros, E.; Zensus, J. A.; Vermeulen, R. C. Doppler Boosting, Superluminal
Castillo, Bernal. The Conquest of New Spain. Penguin Classics. J. M. Cohen(英语:J. M. Cohen) (trans.) 6th printing (1973). Harmondsworth, England: Penguin
Bibcode:1984A&AS...58..735B. Cohen, Judith G.; Blakeslee, J. P.; Côté, P., The Ages and Abundances of a Sample of Globular Clusters in M49 (NGC 4472), The Astrophysical