Nos. (2) and (3) give us the result here shown; and now we need not trouble about No. (1), as the Proposition “Some m are x ” is already represented on the Diagram.
— from Symbolic Logic by Lewis Carroll

There are twenty bales, marked "A. X." I am told, by judges in the trade, that they are the best and cheapest that can be had.
— from The Gentleman's Model Letter-writer A Complete Guide to Correspondence on All Subjects, with Commercial Forms by Anonymous

Indian mounds at, xxvii Ioway and Sac Mission Press, 7 , note “Ioway District,” 2 , note Ioway Club, The.
— from The Iowa by Foster, Thomas, of Washington, D.C.

Of course, between ourselves we know perfectly well how matters stand, and that we can't make an X into a Y. Believe me, were it not for the drop of Frankish blood that I got from my mother, I should not be so naïf as to blurt out our national secret to you.
— from In Paradise: A Novel. Vol. I. by Paul Heyse