Speak up! a work text in speech and oral communication অনুযায়ী Maglaya, Rommel, De Guzman, Algene M., Medrano, Myrna O., Lim, Jennifer J., Constantino, Guia F., Desacado, Christine Joanne L., Malonzo, John Hayrold C., Villanueva, Sherill D.