Παραπομπή σε μορφή APA (7η εκδ.)

Northwestern University, Evanston, Ill. Dept. of Geography. (1952). The rural land classification program of Puerto Rico. s.n.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Northwestern University, Evanston, Ill. Dept. of Geography. The Rural Land Classification Program of Puerto Rico. Evanston, Ill: s.n, 1952.

Παραπομπή σε μορφή MLA (9th εκδ.)

Northwestern University, Evanston, Ill. Dept. of Geography. The Rural Land Classification Program of Puerto Rico. s.n, 1952.