Teaching school mathematics, edited by W. Servais and T. Varga. Servais, Willy. Varga, Tamás, joint author. Mathematics Study and teaching (Secondary) QA11 .S46 510.7 SET Includes index Bibliography: p. 289-298. Harmondsworth, Penguin, 1971. 1971. 1971 Text 308 p. eng A Unesco source book Penguin education