Rule 18 of the Bluebook requires the use and citation of traditional printed sources when available, unless there is a digital copy of the source available that is authenticated, official, or an exact copy of the printed source. Generally, the Bluebook encourages authors to find and use the hardcopy of the sources; however, if the researchers cannot find the hard copies of the materials they should use the most current internet materials.
Generally, the Bluebook establishes three general formats for structuring a citation. These three general formats are:
Under Rule 18.2 – Internet Citations, authors should cite directly to an internet source when a source does not exist in a traditionally printed form or commercial database. If the internet source is identical to the print source, authors may include a parallel cite to the internet source preceded by "available at." Authors should cover the following elements:
Example: Faith Karimini, What Jeff Sessions Said about Russia Ties during Confirmation Hearings (last updated, March 3, 2017), available at http://www.cnn.com/2017/03/02/politics/russia-jeff-sessions-confirmation-hearing/index.html [https://perma.cc/K7A7-5AVA].