Villanueva, P. M. (1989). English skills for college freshmen. Katha Pub.
Chicagoスタイル(17版)引用形式Villanueva, Perla M. English Skills for College Freshmen. Quezon City: Katha Pub, 1989.
MLA(9版)引用形式Villanueva, Perla M. English Skills for College Freshmen. Katha Pub, 1989.
警告: この引用は必ずしも正確ではありません.