http://tobaccodocuments.org/ahf/00115882-5887.html
Bell, J.H.; Perini, F.R. "Nitrosation Suppression During Laboratory Fermentation of Pf2-760000 Tobacco". 20 Feb 1979. Bates: 00115882-5887. http://tobaccodocuments.org/ahf/00115882-5887.html