Jo

 –  Takes seven seconds of Googling.

 –  On the Wikipedia page.

 –  In every book on the subject, incredibly basic part of the field.

 –  Most undergrads in the field can tell you.

 –  Most everyone who works in the field can tell you.

 –  Most everyone who works in the field can figure it out in short order, because either one of their colleagues knows it or it's in one of the well-known and respected books.

 –  You have to spend a day at the library, plus another day once the book you've requested from the Harvard Depository arrives.

 –  You have to check the indices of all 72 books on the subject at the Library of Congress.

 –  You have to check the indices of all 1137 books on the subject, and the one you need is at some random university library thirteen hundred miles away.

 –  It's randomly buried in an obscure book on the subject, and not indexed in any way.

 –  It's randomly buried in some random book in the university stacks.

 –  It's randomly buried in some random book somewhere.

 –  Not extant.