APA (7e ed.) Bronvermelding

De Leon, H. S., & De Leon, H. M., Jr. (2011). The law on obligations and contracts (2011 revised edition.). Rex Book Store.

Chicago (17e ed.) Bronvermelding

De Leon, Hector S., en Hector M. De Leon, Jr. The Law on Obligations and Contracts. 2011 revised edition. Manila: Rex Book Store, 2011.

MLA (9e ed.) Bronvermelding

De Leon, Hector S., en Hector M. De Leon, Jr. The Law on Obligations and Contracts. 2011 revised edition. Rex Book Store, 2011.