^According to Steven H. Weintraub in his memorial tribute to Everett Pitcher in the Notices of the AMS, the paper, by A. Everett Pitcher and John L. Kelley, Exact homomorphism sequences in homology theory "marks the first appearance in print of the term "exact sequence", now ubiquitous in algebraic topology. (This term had been invented by Eilenberg and Steenrod and was to appear in their book Foundations of Algebraic Topology, which was first published in 1952.)"
^Kelley, J. L.; Pitcher, Everett (1947). "Exact homomorphism sequences in homology theory". Ann. Math. 48 (3): 682–709. doi:10.2307/1969135. JSTOR1969135.