1. Peimbert, M., and Serrano, A. 1980, Rev, Mexicana Astron, and
Astrophys., 5, 9 (r = 10 kpc).
2. Kaler, J.B. 1978, Ap. J., 226, 947.
3. Barker, T. 1978, Ap. J., 221, 145, Group I.
4. Barker, T. 1978, Ap. J., 221, 145, Group II.
5. Present survey, r = 10 kpc.