Bloomberg Law (a database that combines legal and business materials - created in 2009 (requires a separate password as do Westlaw & Lexis Plus) - is a much newer and less comprehensive database than Westlaw or Lexis Plus.
Bloomberg Law is growing rapidly - and in particular is filling the void when it comes to more extensive business resources (which may not be included Westlaw or Lexis Advance).
For a more extensive listing of titles (specifically "Secondary Sources" dealing with Banking & Finance, Commercial Law, Corporations & Securities Law):
Sign on to Bloomberg Law
I. Banking and Finance Law
American Factoring Law - Bloomberg Law
Banking and Finance Practice Center - Bloomberg Law
II. Commercial Law
Please look to the other Resource Tabs for Commercial Law titles.
Corporate Director's Guidebook - Bloomberg Law (6th ed. 2011 - ABA - avail in Law Stacks as well)
Corporate Practice Center - Bloomberg Law
IV. Securities Law