SILICA SUPPORTED PERCHLORIC ACID (HCLO4-SIO2) AS ECOFRIENDLY REUSABLE CATALYSTS FOR GREEN SYNTHESIS OF TETRAHYDROBENZO[B]PYRAN DERIVATIVES BY GRINDING METHOD. (2022). International Journal of Food and Nutritional Sciences, 11(12), 3348-3353. http://www.ijfans.org/index.php/Journal/article/view/13213