Παραπομπή APA

Penrose, R. (2011). Roger penrose collected works. Vol.3.

Παραπομπή Chicago Style

Penrose, Roger. Roger Penrose Collected Works. Vol.3. Oxford Clarendon Press, Oxford, 2011.

Παραπομπή MLA

Penrose, Roger. Roger Penrose Collected Works. Vol.3. 2011.