Abdelhamid, Abdou Osman, et al. “Convenient Synthesis of Some New pyrazolo[5,1-c]triazines, isoxazolo[3,4-D] Pyrimidine and Pyridine Derivatives Containing Benzofuran Moiety”. European Journal of Chemistry, vol. 3, no. 2, June 2012, pp. 129-37, doi:10.5155/eurjchem.3.2.129-137.579.