1. J. Kerr, Seventy-First Meeting of the British Association for the Advancement of Science (Spottiswoode and Co. LTD., 1901); available at https://www.biodiversitylibrary.org/item/93257#page/5/mode/1up.
2. A. Cotton, Notice sur les travaux scientifiques, https://www.academie-sciences.fr/pdf/dossiers/Cotton/Cotton_pdf/Cotton_notice.pdf.