If you know the statutory code section:
The United States Code (USC) is located on range 46, 3rd floor, or online on the Government Printing Office site’s United States Code page. USCA is located in range 63, 1st floor reference collection and on Westlaw, while USCS is in range 47, 3rd floor and LexisNexis.
This service is arranged by Internal Revenue Code (IRC) section. It is a four-in-one tool. At the beginning of the set you will find two volumes labeled “Internal Revenue Code,” which contains the current version of the IRC. The second part of the set has seventeen volumes containing the text of each code section followed by its legislative history annotations, the full text of related regulations, and annotations to court decisions (i.e. TC, TCM, U.S., F., F.2d, F.3d, and F.Supp.), Revenue Rulings (Rev. Rul.), etc. Part three is the two-volume Citator. Part four is the U.S. Tax Cases Advance Sheets. Each year has its own set of volumes, going back to 1954.