Plane & spherical trigonometry :  a tetrahedron approach / 
Millard R. Mamhot ; Joemar C. Endan ; Alice A. Mamhot ; Emelyn C. Banagua ; Jenette S. Bantug 
 - Manila :  Unlimited Books Library Services & Publishing Inc.,  2015. 
 - vi, 214 p.; 22.9cm. 
<br/><br/>includes appendix, index, references 
<br/><br/><label>ISBN: </label>9789719654056 
<br/><br/><label>Dewey Class. No.: </label>Fil 516 P712 2015