SEARCH Articles Figures Tables Hermecz, I., Vasvari-Debreczy, L., Tricyclic Compounds with a Central Pyrimidine Ring Pyrimidines rings Tricyclic Compounds Tricyclic compounds with a central pyrimidine ring and Tricyclic compounds with a central pyrimidine ring and one bridgehead Tricyclic compounds with a central pyrimidine ring and one bridgehead nitrogen