If the Literature Review limit doesn't appear under the Literature Types menu, it means that there are no literature reviews in your original search results. You may want to broaden your search, then try limiting to literature reviews again.
If the Literature Types menu doesn't appear, be sure you are searching BIOSIS Previews and not All Databases, Web of Science Core Collection, or any other Web of Knowledge database. Go to the Search page and select BIOSIS Previews from the drop-down menu next to Search in:
Other databases such as PubMed, Web of Science Core Collection, and Scopus also enable you to limit to literature reviews; if you need help, please contact a librarian.