GIES, D. R., BOLTON, C. T., BLAKE, R.M., CABALLERO-NIEVES, S.M., CRENSHAW, D. M., HADRAVA, P., HERRERO, A., HILLWIG, T.C., HOWELL, S.B., HUANG, W., KAPER, L., KOUBSKÝ, P., MCSWAIN, M.V. Stellar Wind Variations during the X-Ray High and Low States of Cygnus X-1. Astrophysical Journal. 2008, 678(2), 1237-1247. ISSN 0004-637X. E-ISSN 1538-4357. Dostupné z: https://doi.org/10.1086/586690