Patai, Saul, ed. (1975-01-01). The Chemistry of the Hydrazo, Azo and Azoxy Groups. The Chemistry of Functional Groups. Vol. 1. Chichester, UK: John Wiley & Sons, Ltd. doi:10.1002/0470023414. ISBN978-0-471-66924-1.
Guideline On The Limits Of Genotoxic Impurities "Archived copy"(PDF). Archived from the original(PDF) on 2006-09-04. Retrieved 2007-07-11.{{cite web}}: CS1 maint: archived copy as title (link)
Guideline On The Limits Of Genotoxic Impurities "Archived copy"(PDF). Archived from the original(PDF) on 2006-09-04. Retrieved 2007-07-11.{{cite web}}: CS1 maint: archived copy as title (link)