Unsold, A., Baschek, B., Kegel, W. H., & Traving, G. (1975). Problems in stellar atmospheres and envelopes. Springer-Verlag.

Unsold, Albrecht, B. Baschek, Wilhelm H. Kegel, and G. Traving. Problems in Stellar Atmospheres and Envelopes. Berlin ; New York: Springer-Verlag, 1975.

Unsold, Albrecht, et al. Problems in Stellar Atmospheres and Envelopes. Springer-Verlag, 1975.