De Leon, H. S. (1969). The law on obligations and contracts. s.n.
Chicagoスタイル(17版)引用形式De Leon, Hector S. The Law on Obligations and Contracts. [Manila: s.n, 1969.
MLA(9版)引用形式De Leon, Hector S. The Law on Obligations and Contracts. s.n, 1969.
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