1. 1-Ethyl-3-methylquinoxalin-2(1H)-one;Acta Crystallographica Section E Structure Reports Online;2008-10-31
2. Nitro and Nitroso Dyes;Ullmann's Encyclopedia of Industrial Chemistry;2000-06-15
3. Hair colourants;Poucher’s Perfumes, Cosmetics and Soaps;2000
4. Hair colourants;Poucher’s Perfumes, Cosmetics and Soaps;1993
5. Hair Colouring;Review of Progress in Coloration and Related Topics;1985-06