Yamada, H.; Okamoto, T.. A One-step Synthesis of Purine Ring from Formamide. Chemical & Pharmaceutical Bulletin, 1972, s.623. Dostupné online. DOI:10.1248/cpb.20.623.
Yamada, H.; Okamoto, T.. A One-step Synthesis of Purine Ring from Formamide. Chemical & Pharmaceutical Bulletin, 1972, s.623. Dostupné online. DOI:10.1248/cpb.20.623.