1. Alzner, A., & Argyle, R. W. 2000, IAU Comm., 26 Circ., 142
2. Argyle, R. W., & Alzner, A. 2001, IAU Comm., 26 Circ., 143
3. Alzner, A., & Argyle, R. W. 2001, IAU Comm., 26 Circ., 144
4. Cox, A. N. (ed.) 1999, Allen's Astrophysical Quantities, 4th ed. (Springer, Berlin)