OpenIntro Statistics is an open-source textbook for introductory statistics written by David Diez, Christopher Barr, and Mine Çetinkaya-Rundel.[1][2][3] It is one of three open-source statistics textbooks that the American Institute of Mathematics has approved for use at the university undergraduate level.[4]
The textbook is available online as a free PDF, as LaTeX source and as a royalty-free paperback.[5]