Servais, Willy. Teaching school mathematics, edited by W. Servais and T. Varga. - Harmondsworth, Penguin, 1971. - 308 p. illus. (some col.) 21 cm. - A Unesco source book Penguin education . Bibliography: p. 289-298. ISBN: 0140800840 LCCN: 72883583 Nat. Bib. No.: B71-23919 Subjects--Topical Terms: Mathematics--Study and teaching (Secondary) LC Class. No.: QA11 / .S46 Dewey Class. No.: 510/.71/2