Kokel, B., Lespagnol, C., & Viehe, HG. (1980). Phosgeniminium Salts .28. Annelation of 5-membered Or 6-membered Heterocycles To Uracil Derivatives Via Phosgeniminium Salt Condensation. Societes Chimiques Belges. Bulletin, 89(8), 651-657. https://doi.org/10.1002/bscb.19800890808 (Original work published 1980)