Current problems of lower vertebrate phylogeny proceedings of the Fourth Nobel Symposium held in June 1967 at the Swedish Museum of Natural History (Naturhistoriska riksmuseet) in Stockholm
Orvig, Tor.
Nobel Symposium(4th :1967 :Stockholm)
New York Chichester Interscience
1968
Originally published, Stockholm: Almqvist & Wiksell, 1968
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