Whelan, P. M. Essential principles of physics / By P. M. Whelan and M. J. Hodgson. - 2nd ed. - England: John Murray Publishers, c1978. - ix, 493p.: ill.: 22 cm. Includes and index. Source: B-3381 Subjects--Topical Terms: Physics. LC Class. No.: QC23 / .W43 1978