In Euler's Lettres à une princesse d'Allemagne sur divers sujets de physique et de philosophie [Letters to a German Princess on various physical and philosophical subjects] (Saint Petersburg, Russia: l'Academie Impériale des Sciences, 1768), volume 2, pages 95-126. In Venn's article, however, he suggests that the diagrammatic idea predates Euler, and is attributable to Christian Weise or Johann Christian Lange (in Lange's book Nucleus Logicae Weisianae (1712)).
Mac Queen, Gailand (October 1967). The Logic Diagram(PDF) (Thesis). McMaster University. Archived from the original(PDF) on 2017-04-14. Retrieved 2017-04-14. (NB. Has a detailed history of the evolution of logic diagrams including but not limited to the Venn diagram.)
Mac Queen, Gailand (October 1967). The Logic Diagram(PDF) (Thesis). McMaster University. Archived from the original(PDF) on 2017-04-14. Retrieved 2017-04-14. (NB. Has a detailed history of the evolution of logic diagrams including but not limited to the Venn diagram.)