Government Documents has an extensive collection of federal regulations, including the following:
Federal register (AE 2.106:) Proposed regulations, meeting announcements, executive orders and proclamations, and other legally required announcements are issued in this daily publication. Read this tutorial to learn more. Look at recent issues in Govinfo (1980-present) or on each agency's web site. Older issues (1936-present) of Federal register are available in HeinOnline (UHM login required) in its Federal register library. You can also search the Federal register in ProQuest Congressional (1981-present; UHM login required), which links the Federal register to the Code of federal regulations.
Code of federal regulations (AE 2.106/3:) The CFR's 50 titles arrange federal regulations by subject. It is updated annually. Search the current CFR in Govinfo (1996-present) or use the eCFR (unofficial version that is updated weekly). Older issues (1938-present) of CFR are available in HeinOnline (UHM login required) in its Federal register library. You can also search the Code of federal regulations in ProQuest Congressional (1981-present; UHM login required), which links the Federal register to the Code of federal regulations.