Regulations are subject to frequent change. It is important to update your research to be sure that you have the current version.
Online sources are generally updated more quickly than print sources. Look at the top of the screen in each source for an indication of how current the source is. The free e-CFR integrates newly adopted regulations.
The List of Sections Affected (LSA) is a tool used to determine if a particular CFR section has been revised by later action published in the Federal Register.
Here is the step-by-step process if you are updating a regulation in the CFR using the List of Sections Affected and the Federal Register.