APA-viite (7. p.)

O'Brien, K., Horne, K., Gomer, R., Oke, J., & van der Klis, M. (2004). High-speed Keck II and RXTE spectroscopy of Cygnus X-2 - I. Three X-ray components revealed by correlated variability.

Chicago-viite (17. p.)

O'Brien, K., K. Horne, R. Gomer, J. Oke, ja M. van der Klis. High-speed Keck II and RXTE Spectroscopy of Cygnus X-2 - I. Three X-ray Components Revealed by Correlated Variability. 2004.

MLA-viite (9. p.)

O'Brien, K., et al. High-speed Keck II and RXTE Spectroscopy of Cygnus X-2 - I. Three X-ray Components Revealed by Correlated Variability. 2004.