炭化ホウ素
↑ “Rutgers working on body armor”. Asbury Park Press. (2012年8月11日). http://www.app.com/article/20120811/NJNEWS/308110051/Rutgers-working-on-body-armor 2012年8月12日閲覧. "... boron carbide is the third-hardest material on earth."
↑ Ridgway, Ramond R "Boron Carbide", European Patent CA339873 (A), publication date: 1934-03-06
1 2 Musiri M. Balakrishnarajan, Pattath D. Pancharatna and Roald Hoffmann (2007). “Structure and bonding in boron carbide: The invincibility of imperfections”. New J. Chem. 31 (4): 473. doi:10.1039/b618493f. http://www.