Koch, Werner (2013). VDI Steam Tables (4 ed.). Springer. p. 8. ISBN9783642529412. Published under the auspices of the Verein Deutscher Ingenieure (VDI).
International Union of Pure and Applied Chemistry, Physical Chemistry Division. "Quantities, Units and Symbols in Physical Chemistry"(PDF). Blackwell Sciences. p. 7. The adjective specific before the name of an extensive quantity is often used to mean divided by mass.