APA (7 वां संस्करण) प्रशस्ति पत्र

GENTRY GEORGE. (1978). HARDENING & TEMPERING ENGINEERS TOOLS. MODEL AND ALLIED.

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

GENTRY GEORGE. HARDENING & TEMPERING ENGINEERS TOOLS. WATFORD: MODEL AND ALLIED, 1978.

एमएलए (9वां संस्करण) प्रशस्ति पत्र

GENTRY GEORGE. HARDENING & TEMPERING ENGINEERS TOOLS. MODEL AND ALLIED, 1978.