APA (7 वां संस्करण) प्रशस्ति पत्र

Williams, G. (2002). Biology for you: Revised national curriculum edition for GCSE ([2nd ed.].). Nelson Thornes.

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

Williams, Gareth. Biology for You: Revised National Curriculum Edition for GCSE. [2nd ed.]. Cheltenham, U.K: Nelson Thornes, 2002.

एमएलए (9वां संस्करण) प्रशस्ति पत्र

Williams, Gareth. Biology for You: Revised National Curriculum Edition for GCSE. [2nd ed.]. Nelson Thornes, 2002.