Liwanag, Ma. Ruby Anne M. ECOTAR : fundamentals of college economics with taxation and agrarian reform / Ma. Ruby Anne Maroma-Liwanag [and three others]. - revised edition. - Mandaluyong City : Books Atbp. Publishing Corp, 2014. - vii, 278 pages : Illustrations ; 22 cm. References: p.275-278. Subjects--Topical Terms: Economics.Taxation.