Engle, S. G.; Guinan, E. F.; Harper, G. M.; Neilson, H. R.; Evans, N. R. (2014). “THE SECRET LIVES OF CEPHEIDS: EVOLUTIONARY CHANGES AND PULSATION-INDUCED SHOCK HEATING IN THE PROTOTYPE CLASSICAL CEPHEID δ Cep”. The Astrophysical Journal. 794: 80. arXiv:1409.8628. Bibcode:2014ApJ...794...80E. doi:10.1088/0004-637X/794/1/80.
Engle, S. G.; Guinan, E. F.; Harper, G. M.; Neilson, H. R.; Evans, N. R. (2014). “THE SECRET LIVES OF CEPHEIDS: EVOLUTIONARY CHANGES AND PULSATION-INDUCED SHOCK HEATING IN THE PROTOTYPE CLASSICAL CEPHEID δ Cep”. The Astrophysical Journal. 794: 80. arXiv:1409.8628. Bibcode:2014ApJ...794...80E. doi:10.1088/0004-637X/794/1/80.
Engle, S. G.; Guinan, E. F.; Harper, G. M.; Neilson, H. R.; Evans, N. R. (2014). “THE SECRET LIVES OF CEPHEIDS: EVOLUTIONARY CHANGES AND PULSATION-INDUCED SHOCK HEATING IN THE PROTOTYPE CLASSICAL CEPHEID δ Cep”. The Astrophysical Journal. 794: 80. arXiv:1409.8628. Bibcode:2014ApJ...794...80E. doi:10.1088/0004-637X/794/1/80.
Uesugi, Akira; Fukuda, Ichiro (1970), “Catalogue of rotational velocities of the stars”, Contributions from the Institute of Astrophysics and Kwasan Observatory, University of Kyoto, Bibcode:1970crvs.book.....U.