Among the low points in an American legal education is the law student’s first encounter with The Bluebook, a 582-page style manual formally known as “A Uniform System of Citation.” It is a comically elaborate thicket of random and counterintuitive rules about how to cite judicial decisions, law review articles and the like. It is both grotesque and indispensable.

The Harvard Law Review has long claimed credit for creating The Bluebook. But a new article from two librarians at Yale Law School says its rival’s account is “wildly erroneous.” The librarians, Fred R. Shapiro and Julie Graves Krishnaswami, have done impressive archival research and make a persuasive case that their own institution is the guilty party.

“It’s clear that the idea of a uniform citation manual came from Yale, and a lot of the specifics of the early rules came from Yale,” Mr. Shapiro said in an interview. “Harvard entered into the picture later.”

Mr. Shapiro, a graduate of Harvard Law School, said he knew that his employer might take little pride in his discoveries. “The Bluebook is criticized more than it’s praised,” he said. “It is often criticized for being terribly complicated.”