Cita APA (7th ed.)
Pennington, A. (1954). Concrete Farm Structures.
Cita Chicago (17th ed.)
Pennington, A.M. Concrete Farm Structures. 1954.
Cita MLA (9th ed.)
Pennington, A.M. Concrete Farm Structures. 1954.
Atenció: Aquestes cites poden no estar 100% correctes.