Cita APA (7th ed.)
Silk, J. A Short History of the Universe. Scientific American.
Cita Chicago (17th ed.)
Silk, Joseph. A Short History of the Universe. Nueva York, EUA: Scientific American.
Cita MLA (9th ed.)
Silk, Joseph. A Short History of the Universe. Scientific American.
Atenció: Aquestes cites poden no estar 100% correctes.