Shafi, S.; Chand, A.; Nawaz, M.; Parveen, R.; Munawar, S.; Ishfaq, M.; Sheikh, M.; Maryam, A.; Saleem, T. Facile Synthesis of 5,6,7,8-tetrahydropyrimido[4,5-D] Pyrimidine-2,4 (1H,3H) -Dione Analogs via One Pot Multicomponent Reaction . FCS 2020, 1, 1-7.