IRS Tax Code, Regulations, & Official Guidance
West's Federal Tax Regulations - The library's subscription was cancelled as of 2010.
Federal tax law can be found in Title 26 of the United States Code (U.S.C.). This title is also known as the Internal Revenue Code (I.R.C.). You can access Title 26 online, through the GPO's FDsys website, or in bound format at the Library.
HeinOnline: Taxation & Economic Reform in America Parts I & II.
United States Code Congressional & Administrative News (USSCAN)