Pfeifer, Niki. «Lorne Szabolcsi, Numerical Term Logic (edited by George Englebretsen, Foreword by Fred Sommers), Lewiston, New York: The Edwin Mellen Press, 2008, xii+119pp., ISBN 0-7734-5027-0». Cogency 1, no. 2 (mayo 28, 2009). Accedido octubre 19, 2025. https://cogency.udp.cl/index.php/cogency/article/view/216.