Radio recombination lines : 25 years of investigation.
Dordrecht : Kluwer, 1990.
298 págs.
Serie: Astrophysics and space science library ; no. 163
ISBN: 0792308042
Proceedings of the 125th Colloquium of the International Astronomical Union, held in Puschino, U.S.S.R., september 11-16, 1989.