National Council of Teachers of Mathematics, U.S.A. (1970). Lógica. Trillas.
Chicago-čujuhus (17. p.)National Council of Teachers of Mathematics, U.S.A. Lógica. Ciudad de México: Trillas, 1970.
MLA-čujuhus (9. p.)National Council of Teachers of Mathematics, U.S.A. Lógica. Trillas, 1970.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.