Heppenstall Company. Metallurgical Dept. (1948). Effects of alloying elements and the tensile and hardness properties of carbon and alloy steel (Rev. ed.). s.n.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHeppenstall Company. Metallurgical Dept. Effects of Alloying Elements and the Tensile and Hardness Properties of Carbon and Alloy Steel. Rev. ed. Pittsburgh: s.n, 1948.
एमएलए (9वां संस्करण) प्रशस्ति पत्रHeppenstall Company. Metallurgical Dept. Effects of Alloying Elements and the Tensile and Hardness Properties of Carbon and Alloy Steel. Rev. ed. s.n, 1948.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.