... 2004, Egyptian Journal of Chemistry more. Swelam SA , Fathalla OA , Zak MEA , Aly HF. Synthesis of pyrido [2,1-c] [1,2,4] triazine,1,2,4 triazolo [4,3-a] pyridine and 2-(substituted-pyrazolyl) nicotinonitrile and their effect on biomphalaria alexandrina snail enzymes. ...