A. Ragab, Yousif, & George B. Butler. " Electron Donor Acceptor Complexes and Copolymerization Behavior of Oxazole and Thiazole with Maleic Anhydride. A Comparison with Other Five-Membered Heterocyclic Donors." Gezira Journal of Engineering and Applied Sciences [Online], 9.1 (2014): n. pag. Web. 3 Jun. 2026