You can search for ebooks specifically by checking the «show only ebooks» box under the main search box. (lifewire.com)
To determine if Lexis provides access to a certain source, use Lexis» Browse function or just try typing the name of the source in the main search box. (law.miami.edu)
To determine if Westlaw provides access to a source, try typing the name of the source in the main search box. (law.miami.edu)