Dyfyniad APA

Hawking, L., & Hawking, S. W. G. (2007). George's secret key to the universe. Doubleday.

Dyfyniad Arddull Chicago

Hawking, Lucy, and Stephen W. Galfard Hawking. George's Secret Key to the Universe. London: Doubleday, 2007.

Dyfyniad MLA

Hawking, Lucy, and Stephen W. Galfard Hawking. George's Secret Key to the Universe. Doubleday, 2007.

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