Baltazar, Ethel Cecille M. Plane and spherical trigonometry / Ethel Cecille M. Baltazar, Ana Liza M. Dy, Melvin A. Vidar. - Quezon City : C & E publishing, 2014. - ix, 257 p. : black and white illustrations ; 26 cm. Includes references. ISBN: 978 971 980 164 1 Subjects--Topical Terms: Plane trigonometry.Spherical trigonometry.Trigonometry. Dewey Class. No.: FIL 516.24 B21p 2014