1. Batten,A.H.: 1989, Space Science Reviews, 50, 1.
2. Budding, E.: 1985, Publ. Astron. Soc. Pacific, 97, 584
3. Cester,B.,Giuricin,G.,Mardirossian,F.,Mezzetti,M.,Maceroni,C. and Mancuso,S.: 1979, Astron. Astrophys., 73, 31
4. Claret, A.: 1989, Private communication.
5. Claret,A. and Giménez,A.: 1989, Astron. Astrophys. Supl., 81, 1