1. J. Roberts and M. Caserio, Basic Principles of Organic Chemistry (Addison-Wesley, Reading, MA, 1977; Mir, Moscow, 1968), Part 2.
2. P. Gordon and P. Gregory, Organic Chemistry in Color (Springer, Berlin, 1983; Mir, Moscow, 1987).
3. I. M. Kogan, Chemistry of Dyes (Synthetic) (ONTI, Glavnaya Redaktsiya Khim. Lit, Moscow, 1938) [in Russian].
4. I. M. Kogan, Chemistry of Dyes (Goskhimizdat, Moscow, 1956) [in Russian].
5. K. D. Nenitsesku, Organic Chemistry, II (Inostr. Liter., Moscow, 1963) [in Russian].