Fabra, Norberto F. <br/><br/>
Trigonometry for secondary schools / 
Norberto F. Fabra. 
 - Rev. ed. 
 - Las Pinas, MM :  Fabra N.F. Educational Books,  1994. 
 - viii, 296 p. : ill. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Trigonometry--Study and teaching (Secondary)