Carroll is the author of Becoming a Critical Thinker, a textbook for introductory logic and critical thinking courses. It covers subjects such as language and critical thinking, the mass media and other sources of information, fallacies of reasoning, and inductive and deductive arguments. The book is subtitled A Guide for the New Millennium. Pearson Educational published the first edition in 2000 and the second edition was published in 2005. Becoming a Critical Thinker was born out of Carroll's classwork during his time in Sacramento City College. The Skeptic's Dictionary is the print version of the website skepdic.com and is available in Dutch, English, Japanese, Korean, and Russian. It provides definitions, arguments, and essays on supernatural, occult, paranormal, and pseudo-scientific subjects. The book features many examples of pseudoscientific beliefs over its eight chapters. In the last chapter, Carroll provides ways to improve critical thinking and skepticism. Similar to the website, it takes a skeptical stance, typically assuming that something is false until proven otherwise. The book came about when Ted Weinstein, a literary agent, contacted Carroll about creating the book. The book was eventually published by John Wiley & Son in August 2003 as an inexpensive paperback. The book is intended to be biased towards the skeptical side; it is not targeted towards true believers. Carroll also wrote a children's version of the Skeptic's dictionary which was released online on July 22, 2011. In 2013, it was published as a children's book under the title Mysteries and Science: Exploring Aliens, Ghosts, Monsters, the End of the World and Other Weird Things. He also wrote Unnatural Acts: Critical Thinking, Skepticism, and Science Exposed! which was initially published by the James Randi Educational Foundation as an e-book in 2011. A paperback version is available from Lulu. The Critical Thinker's Dictionary was published in 2013. It features short articles about cognitive biases and logical fallacies.

Answer this question "What else did he write about?" by extracting the answer from the text above.
He also wrote Unnatural Acts: Critical Thinking, Skepticism, and Science Exposed!