| Ullmann's Encyclopedia of Industrial Chemistry, 5th Completely Revised Edition, vol. A20, pp. 407-408. |
| Herbst et al., Industrial Organic Pigments, pp. 514-518. |
| D. Stevenson & G.T. Young, J. Chem. Soc. �c! 1969, 2389. |
| Roberts et al., Modern Organic Chemistry, 1967, Chapter 28, pp. 682-687. |
| Herbst et al., Industrial Organic Pigments, Production, Properties, Applications. |
| Tetrahedron Letters, vol. 24, No. 3, pp. 231-232, (1983). |
| J.C.S. Perkin I Acyl Nitroxides, Part 1, Synthesis and Isolation, pp. 1066-1076, (1978). |