Advanced trigonometry / C.V. Durell and A. Robson Durell, Clement V. (Clement Vavasor), 1882- Robson, A. (Alan), 1888- joint author. Trigonometry. QA531 .D786 1934 514 DUA includes index London : G. Bell and Sons, c1934. c1934. 1934 Text viii, 335(1) p. : eng