Kemeny, John G. Introduction to finite mathematics [electronic resource] / [by] John G. Kemeny, J. Laurie Snell [and] Gerald L. Thompson.. — 2d ed.. — Englewood Cliffs, N.J., : Prentice-Hall, [1966]. — xiv, 465 p. : illus. 22 cm. - Prentice-Hall mathematics series.