1. Astbury, T.H.: Astron. Nachr. 182, 389 (1909)
2. Bradstreet, D.H.: Light Curve Modeling of Eclipsing Binary Stars. Springer, Berlin (1993); p. 151
3. Broglia, P.: J. Obs. 47, 99 (1964)
4. Cester, B., Fedel, B., Giuricin, G., Mardirossian, F., Pucillo, M.: Astron. Astrophys. 61, 469 (1977)
5. Covino, E., Milano, L., de Martino, D., Vittone, A.A.: Astron. Astrophys. Suppl. Ser. 73, 437 (1988)