Παραπομπή APA

Penrose, R. (2010). Cycles of time: An extraordinary new view of the universe. Vintage Books.

Παραπομπή Chicago Style

Penrose, Roger. Cycles of Time: An Extraordinary New View of the Universe. London: Vintage Books, 2010.

Παραπομπή MLA

Penrose, Roger. Cycles of Time: An Extraordinary New View of the Universe. Vintage Books, 2010.