to materials for the purpose of research or independent study Nothing in this section shall be construed to prevent individuals from accessing materials that advocate theories described under subsection (a) for the purpose of research or independent study. (3) Contextual education Nothing in this section shall be construed to prevent the United States Armed Forces and academic institutions operated or controlled by the Department of Defense from stating theories described under subsection (a) or assigning materials that advocate such theories for educational purposes in contexts that make clear the United States Armed Forces and Department of Defense does not sponsor, approve, or endorse such theories or works.