Pierre Jacquet, "History of Orchids in Europe, from Antiquity to the 17th Century," ''Orchid Biology: Reviews and Perspectives 6 (1994), as cited by Joseph Arditti, Orchid Biology (Kluwer Academic Publishers, 2002), p. 27 online.
uchicago.edu
penelope.uchicago.edu
R.H. Allen, Star Names: Their Lore and Meaning. Bill Thayer's editie bij LacusCurtius, "Cassiopeia." De supernovarest staat nu bekend als SN 1572.
uni-mannheim.de
Melchior Adam, "Cornelius Gemma" in Vitae Germanorum medicorum (1620), p. 239 online facsimile.
web.archive.org
University of Oklahoma Libraries, History of Science Collections, Recente Acquisities, "The First Book Printed on Tycho Brahe's Printing Press at Uraniborg: Diarium, 1586," The Lynx 2 (November 2005), p. 9 online met Gemma's illustratie.
