Optimizing Amorphous Silica Recovery from Rice Husk Cultivated under Different Soils for Supplementary Cementitious Material Application oleh Pham Viet Hung, Ve Quoc Linh, Vo Cong Anh, Do Thanh Tien, Ngo Quy Tuan, Tran Duc Hanh, Dao Van Phu, Nguyen Thi Thanh, Pham Xuan Phuong, Pham Thi Thanh Phuc