Seada, M., A.M. Abdel-Halim, S.S. Ibrahim, and M. Abdel-Megid. 2010. “Synthesis and Biological Activities of Some New Pyrazolo [3,4-D] Pyrimidine Derivatives”. Asian Journal of Chemistry 4 (3):588-96. https://asianpubs.org/index.php/ajchem/article/view/25100.