SILICA SUPPORTED PERCHLORIC ACID (HCLO4-SIO2) AS ECOFRIENDLY REUSABLE CATALYSTS FOR GREEN SYNTHESIS OF TETRAHYDROBENZO[B]PYRAN DERIVATIVES BY GRINDING METHOD. IJFANS [Internet]. 2022 Jan. 1 [cited 2026 Aug. 24];11(12):3348-53. Available from: http://www.ijfans.org/index.php/Journal/article/view/13213