Παραπομπή σε μορφή APA (7η εκδ.)

Douglas-Cooper, H. (1999). As 70 maravilhas do mundo moderno. Selecções do Reader's Digest.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Douglas-Cooper, Helen. As 70 Maravilhas Do Mundo Moderno. Selecções do Reader's Digest, 1999.

Παραπομπή σε μορφή MLA (8th εκδ.)

Douglas-Cooper, Helen. As 70 Maravilhas Do Mundo Moderno. Selecções do Reader's Digest, 1999.