References
- , Published by permission of the Surgeon General, United States Public Health Service.
- Witt O. N. Ueber neue Farbstoffe. Ber. Deut. Chem. Ges. 1879; 12: 981–939
- This was prepared according according to the method given in L. Vanino's. Präparative Chemie 1923; 2: 669