Applications of Purine Ring Opening in the Synthesis of Imidazole, Pyrimidine, and New Purine Derivatives ; Diazidopurine Ring Opening – Synthesis of Tetrazolylimidazole Derivatives ; Structural Study of Azide-Tetrazole Equilibrium in Pyrido[2,3-d]Pyrimidines ; SNAr Reactions of 2,4-Diazidopyrido[3,2-d]pyrimidine and Azide- Tetrazole Equilibrium Studies of the Obtained 5-Substituted Tetrazolo[1,5-a]pyrido[2,3-e]pyrimidines ; 2,4,6,8-Tetraazidopyrimido[5,4-d]pyrimidine: a Novel Energetic Binary Compound ; Annelētu diazidopirimidīnu drošības profils = Safety Profile of Fused Diazidopyrimidines ; 2,4,6,8-Tetraazidopirido[5,4-d]pirimidīna solvātu sintēze = Synthesis of 2,4,6,8-tetraazidopyrido[5,4-d]pyrimidine solvates.