Παραπομπή σε μορφή APA (7η εκδ.)

Penrose, R. (1972). Techniques of differential topology in relativity. Society for Industrial & Applied Mathematics.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Penrose, Roger. Techniques of Differential Topology in Relativity. Philadelphia, Pennsylvania: Society for Industrial & Applied Mathematics, 1972.

Παραπομπή σε μορφή MLA (9th εκδ.)

Penrose, Roger. Techniques of Differential Topology in Relativity. Society for Industrial & Applied Mathematics, 1972.