Uy, Fausto B. Plane and spherical trigonometry - Manila Merriam Webster Bookstore 2005 - vii, 397 p. : ill. Includes index ISBN: 971-30-1253-4 Subjects--Topical Terms: Trigonometry, PlaneTrigonometry, Spherical Dewey Class. No.: Fil 516.24 Uy1p