Sidgwick, N. V.; Powell, H. M. (1940). «Bakerian Lecture. Stereochemical Types and Valency Groups». Proceedings of the Royal Society of London. 176 (965): 153–180. Bibcode:1940RSPSA.176..153S. doi:10.1098/rspa.1940.0084
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Sidgwick, N. V.; Powell, H. M. (1940). «Bakerian Lecture. Stereochemical Types and Valency Groups». Proceedings of the Royal Society of London. 176 (965): 153–180. Bibcode:1940RSPSA.176..153S. doi:10.1098/rspa.1940.0084