por Sparks, Fred Winchell, 1891- [autor] | Sparks, Fred Winchell, 1891-. Plane trigonometry | Rees, Paul Klein, 1902- [autor] | Amores, Jose Emilio [traductor].
por Sparks, Fred Winchell, 1891- [autor] | Rees, Paul Klein, 1902- [autor] | Amores, Jose Emilio [traductor].