Keele, United Kingdom, in Evans, A.; Bode, M. F.; O'Brien, T. J. et al., RSOphiuchi (2006) and the Recurrent Nova Phenomenon, proceedings of the conference
“The Orbit and Pulsation Periods of the γ Doradus Variable HR 6844 (V2502 Ophiuchi)”, Astronomical Journal 125 (4): 2156-2162, Bibcode: 2003AJ....125.2156F