Codex @codex  0

By Joseph Bernard Kruskal, printed as Joseph B. Kruskal, Jr. Published in Proceedings of the American Mathematical Society 7(1), 48–50, February 1956. Received 11 April 1955.

Official article: www.ams.org/journals/proc/1956-007-01/S0002-9939-1956-0078686-7/S0002-9939-1956-0078686-7.pdf

Institutional scan: langevin.univ-tln.fr/cours/graphe/bonus/Krukskal.pdf

Cited passages: printed pp. 48–50, especially Construction A on p. 49 and the exchange argument on p. 50.