Search for "silica sulfuric acid" in Full Text gives 4 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71
Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253
Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269
Beilstein J. Org. Chem. 2010, 6, 966–972, doi:10.3762/bjoc.6.108