This is a guide to the Bluebook system of American legal citation. The information here can help anyone who is writing a scholarly legal paper in the United States, including JD students, LLM students, and SJD students.
The Bluebook is currently in its 21st edition, released in June 2020. It is available in two formats: as a print book, and as an electronic publication. To buy a print copy or a subscription to the electronic version, visit https://www.legalbluebook.com/.
All references to print book page number in this guide are from the 21st edition.
Below is a two-part recording of a Bluebook training class. It was offered by HLS research librarian Jennifer Allison for LLM students in March 2020. Although it references the 20th edition of the Bluebook, the class is still relevant and provides a good basic introduction to general Bluebook style and citation rules for US and foreign sources.
If you need help navigating the Bluebook or are not sure how to cite a particular source, you are welcome to contact a research librarian for help. Visit https://asklib.law.harvard.edu/ for information about how to get in touch with us.
The HLS research librarians offer Bluebook training classes throughout the academic year. These classes are designed for LLM students who will use the Bluebook citation rules in their LLM papers, but all HLS students are welcome to attend.
Visit the HLS Library Training Calendar (https://libcal.law.harvard.edu/calendar/researchtraining/) to view our training schedule and sign up for a class.
We have some short videos of Bluebook tips that are based on the FAQ in this guide.
The first tip video explains the answers to both FAQ #3 (using id and supra) and FAQ #4 (using Word's internal cross reference feature), all in one 3:30 video!
The next tip video discusses FAQ #2 - using rule 18 to cite online sources. It also talks about perma.cc, the Harvard Law School Library Innovation Lab's website archival tool.
Here's another video that was made based on a recent question we received in the research service department. It describes how to cite a federal statute as a session law (using rule 12.4) and not how it was codified in the U.S. Code. Examples are given for two types of citations: to a chapter number (for very old statutes), or to a public law number (for newer statutes).
The Bluebook has two sections:
Since law school work focuses on academic writing, this guide describes and explains the rules in the Whitepages section.
Table 1 (p. 227) has jurisdiction-specific rules for citing U.S. federal and state cases, statutes, and other primary legal materials.
Table 2 has rules for citing sources from selected foreign jurisdictions. It is no longer in the print version of the Bluebook, but it is freely available online at https://www.legalbluebook.com/bluebook/v21/tables/t2-foreign-jurisdictions.
Tables 3 (international organizations, p. 299) and 4 (treaties, p. 302) have rules for citing international sources.
Finally, many Bluebook rules require certain names, words, and phrases to be shortened. Tables 6-16 (starting on p. 304) list these abbreviations.
Below is list of questions we are often asked about the Bluebook. Answers, with examples, are provided.
Yes! Right inside the front cover there is a quick guide to the major rules, with citation examples. Use this as a quick reference if you can't remember which rule covers which type of source.
Rule 18 has rules for citing internet sources, websites, documents found online, blogs, social media posts, etc.
Remember, the Bluebook really prefers that you cite to a print source. It has gotten more flexible over the years. However, for something like a law review article, even if you found it online, you still need to follow the instructions in Rule 16 to cite it.
Instructions for doing this are in Rule 3.5: Internal Cross-References.
If you cited only one source in footnote #1, and you want to cite the exact same source in footnote #2, that is when you use id. Only the source has to be the same, not the page or section.
For secondary sources like law review articles and books, if you want to cite a source that you cited longer ago in your paper than the previous footnote, you can use supra.
When you do a supra citation, you have to use the same font specifications as you did in the original citation. What does that mean? If you cited a book in the earlier footnote, you put the author's name in small caps. You have to do the same thing in the supra footnote. Footnote #7 in the example below illustrates this.
So what if you want to cite a case (or other primary source) that you have cited before? You cannot use supra for that. Instead, you have two options:
Most LLM papers are in a constant state of flux until they are turned in. Adding footnotes can be a problem if you already have supra references. In the example below, footnote #5 was just added. It cites a different law review article.
Take a look at footnotes #8 and #10 now. The Jackson book is no longer in footnote #5 after this addition, it's now in footnote #6. If you have 200 footnotes already done in your paper, you will have to go back and find each one that cites the Jackson book and change the 5 to a 6. What a pain!
Instead, what you should do from the start is use Microsoft Word's internal cross-reference feature. It's great! Here's how it works.
If you do this, then it is very easy to update all the footnote number references later. Simply click in any footnote, press the Ctrl and A keys at the same time to select all the footnote text, and press the F9 key.
Introductory signals explain why and how you are citing and using a source.They are listed below, and rule 1.2 explains their use.
When using a signal, you may want to add information explaining why you are citing a particular source. See rule 1.5: Parenthetical Information, for how to do this.
Footnotes #13 and #14 have been added to the example (below) to show how signals and parentheticals are used.
Rule 4.2 (p. 81) explains both supra and hereinafter.
One use of hereinafter is if you cite two sources by the same author in the same footnote. You will need a way to distinguish them in later supra references. This is when hereinafter can come in handy. See footnotes #15 and #16 in the example below.
You may be asking why you can't use id. in footnote #16 above. Remember, you can only use id. if the previous footnote cited only one source.
Instructions for citing foreign (non-English) materials are provided in detail in Rule 20.2 and in the individual country sections in Table T2.
Generally, when it comes to language version, you need to cite the source you are referring to, as detailed in rules 20.2.2 and 20.2.5.
In creating these two examples, the following rules were consulted (and some judgment calls were made):
These examples may create more questions than they answer. For example, the German Basic Law is cited in small caps, whereas the Italian constitution is not (and, perhaps, should be). In this case, each of those citations were created according to the jurisdictional rules in T2.
Remember, just do your best.
Cite foreign books just like U.S. books according to rule 15. For articles from foreign periodicals and newspapers, see rule 20.6. They are illustrated in footnotes #19 and #20 below.
Providing an English-language translation of foreign-language article titles is allowed, but not necessary. There is no stated rule on that topic for books.
The Bluebook's capitalization rule, Rule 8, states the following regarding capitalization of words titles:
Incorrect article title:
Hearing the voiceless: a respected judge on putting the rights of crime victims above those of defendants
Correct article title:
Hearing the Voiceless: A Respected Judge on Putting the Rights of Crime Victims Above Those of Defendants
In the text of the article, place the footnote number after any punctuation, including periods, commas, quotations marks, etc.
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