Semaine d'ťude sur le problm̈e des populations stellaires (1957 : Vatican City)
Stellar populations; proceedings of the Conference sponsored by the Pontifical Academy of Science and the Vatican observatory, May 20-28, 1957 / Edited by D.J.K. O'Connell.
Stars -- Congresses.
Astronomy -- Congresses.
O'Connell, D. J. K.
Pontificia Accademia delle scienze