CALI offers an online tutorial on Federal Tax Research that covers "the legislative, administrative, and judicial materials used in the specialized area of tax law". UC Davis Law users can contact lawlibref@ucdavis.edu for a CALI registration code.
Start your federal tax law research with one of the following federal tax treatises or treatise collections.
UC Davis law students have access to a large library of online study aids published by LexisNexis and West Academic. Below is a sampling of our online study aids on federal tax law topics. For more suggestions, browse or search the online collections in LexisNexis Digital Library or West Academic Study Aids.
Federal Estate and Gift Taxation in a Nutshell by 
A Short and Happy Guide to Federal Income Taxation
Tax Procedure and Tax Fraud in a Nutshell