https://api.elsevier.com/content/article/pii/S0013935120312093doi:10.1016/j.envres.2020.1103121-s2.0-S001393512031209310.1016/j.envres.2020.110312S0013-9351(20)31209-3Antiviral activity of natural humic substances and shilajit materials against HIV-1: Relation to structure Environmental ResearchJournal001393512021-02-28February 20210falsefalse