Questia
Access 
A subscription is needed to access the full Questia reference services, as well as research and working tools. Non-subscribers have free access to the library database search results, to table of contents and to some books pages and excerpts.
Fee Policy 
Three different online pay-for-membership plans are available. Subscription is needed for unlimited access to the Questia library. Free access is now granted to more than 500 books, mostly English classics.
Free Retrieved Material
Non-subscribers can search the entire database by keywords and access for free the first page of every chapter in a book and the first paragraph of each article
Linking Richness
Internal circularity and inter-reference within the pages and the sections of this website are quite developed