APA

Pollock F., Wald G. H. & Williston S. (1906). Principles of contract at law and in equity: a treatise on the general principles concerning the validity of agreements in the law of England and America. New York: Baker, Voorhis & company.

Chicago

Pollock Frederick, Wald Gustavus Henry and Williston Samuel. 1906. Principles of contract at law and in equity: a treatise on the general principles concerning the validity of agreements in the law of England and America. New York: Baker, Voorhis & company.

Harvard

Pollock F., Wald G. H. and Williston S. (1906). Principles of contract at law and in equity: a treatise on the general principles concerning the validity of agreements in the law of England and America. New York: Baker, Voorhis & company.

MLA

Pollock Frederick, Wald Gustavus Henry and Williston Samuel. Principles of contract at law and in equity: a treatise on the general principles concerning the validity of agreements in the law of England and America. New York: Baker, Voorhis & company. 1906.