Borabo, Heidi Grace L., Grammar Essentials 1/ Heidi Grace L. Borabo, Joyce M. Cupcupin. - Quezon City: Sibs Publishing House, Inc., 2017. - x, 228 pages: text, illustrations, figures; 28 cm. English ISBN: 9786210005431 Subjects--Topical Terms: Dewey Class. No.: 420 / B726g