De Leon, H. S., & De Leon, H. M. (2000). Comments and cases on obligations and contracts (3rd ed.). Rex Book Store.
芝加哥风格引文De Leon, Hector S., 与 Hector M. De Leon. Comments and Cases on Obligations and Contracts. 3rd ed. Manila: Rex Book Store, 2000.
MLA引文De Leon, Hector S., 与 Hector M. De Leon. Comments and Cases on Obligations and Contracts. 3rd ed. Rex Book Store, 2000.
警告：这些引文格式不一定是100％准确.