Joachim Lambek, Deductive Systems and Categories II: Standard constructions and closed categories, In: Peter Hilton (eds.) Category Theory, Homology Theory and their Applications I, Lecture Notes in Mathematics 86 Springer 1969 (doi:10.1007/BFb0079385, pdf)
Joachim Lambek, The Influence of Heraclitus on Modern Mathematics, In Scientific Philosophy Today: Essays in Honor of Mario Bunge, edited by Joseph Agassi and Robert S Cohen, 111–21. Boston: D. Reidel Publishing Co. (1981)