SIMPSON, J. C. E. Condensed pyridazine and pyrazine rings (Cinnolines, Phthalazines and Quinoxalines) - New York Interscience Publishers, Inc. 1953 - 394 p. - \The \\Chemistry of Heterocyclic Compounds\\Interscience Publishers, New York\ 5 . Source: C-183657 Universal Decimal Class. No.: 547.7