APA (7th ed.) Citation

International Photobiology Congress Copenhagen, International Committee of Photobiology, Christensen, B. C., & Finsen, N. R. (1961). Progress in photobiology: Proceedings. Elsevier.

Chicago Style (17th ed.) Citation

International Photobiology Congress Copenhagen, International Committee of Photobiology, Brge Christian Christensen, and Niels R. Finsen. Progress in Photobiology: Proceedings. Amsterdam: Elsevier, 1961.

MLA (8th ed.) Citation

International Photobiology Congress Copenhagen, et al. Progress in Photobiology: Proceedings. Elsevier, 1961.