Коллеги помогите со статьями (прошу простить что без doi

):
1. J. Heterocycl. Chem., E. F. Elslager, P. Jacob, and L. M. Werbel, "Folate Antagonists. 6. Synthesis and Antimalarial Effects of Fused 2,4-Diaminothieno[2,3-d]pyrimidines" , 1972, 9, 775.
2. J. Heterocycl. Chem., V. J. Ram, H. K. Pandey, and A. J. Vlietinek, "Thieno[2,3-d]pyrimidines as Potential Chemotherapeutic Agents. II." , 1981, 18, 1277.
3. J. Heterocycl. Chem., C. G. Dave, A. B. Shah, and H. C. Shah, "Synthesis and S-Methylation of 2-Thioxopyrido[3',2':4,5]thieno[3,2-d]pyrimidin-4(3H)-ones With and Without a Phase Transfer Catalyst", 1997, 34, 937.
Буду очень признателен
