Chapter 27 of the Legal Information Buyer's Guide & Reference Manual contains a listing of treatises and other sources by topic.
ILW.com provides a listing of immigration resources published by the contributors to the site.
The ImmigrationProf Blog Book Page provides information about new publications in the area of immigration.
The American Immigration Lawyers Association has numerous publications available for purchase.
The Department of State Foreign Affairs Manual (FAM) is available here.