Differential equations by Leopando, Gabriel A., Ramos, Frederick O., Berico, Edwin O., Oliquino, Audie B., Gedaria, Carlito V., Corderro, Marcelino S., Diona, Myrna G., Isaac, Emelita A., Torres, Aureluz, L., Publico, Juan L., Jr, Fadrigalan, Catalina M., Batongbakal, Amalia D.R