9781402749872 | Sterling Pub Co Inc, August 1, 2007, cover price $6.95 | About this edition: Presents a compendium of unusual facts, arranged in such categories as food, animals, the human body, nature, customs, entertainment, and sports.

9781402715488 | Sterling Pub Co Inc, September 1, 2005, cover price $6.95 | About this edition: Presents a compilation of wacky and sometimes icky facts that includes such topics as food, customs, animals, history, nature, and sports.

9780448044422 | Grosset & Dunlap, August 1, 2003, cover price $9.95 | About this edition: A collection of short essays which answer more than 400 questions most consistently asked by children

9780448190693 | Reissue edition (Grosset & Dunlap, May 1, 1988), cover price $9.95 | About this edition: Answers questions about our world, how things began, how things are made, how other creatures live, the human body, and love, families, and babies

9780448225043, titled "Tell Me Why, 4" | Reissue edition (Price Stern Sloan, May 1, 1986), cover price $9.95 | About this edition: Answers questions about UFO's, oats, the Sphinx, Napoleon, fossils, watermelons, covered bridges, hummingbirds, insulin, arthritis, eyes, oysters, wolves, sextants, lipstick, and radio astronomy

9780448225012, titled "Tell Me Why, 1" | Reissue edition (Price Stern Sloan, May 1, 1986), cover price $10.95 | About this edition: A four-volume set containing questions and answers about such things as the world around us and how it began, the human body, how other creatures live, and how things are made.

9780448225029, titled "Tell Me Why, 2" | Reissue edition (Price Stern Sloan, May 1, 1986), cover price $9.95 | About this edition: Answers questions about asteroids, igloos, yeast, porcupines, toucans, blood pressure, vitamin C, beards, superstitions, patents, windmills, tea, cotton, and tunnels

9780448225036, titled "Tell Me Why, 3" | Reissue edition (Price Stern Sloan, May 1, 1986), cover price $9.95 | About this edition: Answers questions about tree rings, quicksand, tornadoes, Pompeii, Socrates, the Vikings, dragons, jellyfish, ESP, sleep, zoos, photography, pirates, gravestones, and camouflage

9780448115368 | Putnam Pub Group, June 1, 1973, cover price $4.95

9780822208099 | Dramatist''s Play Service, October 1, 1972, cover price $7.00

9780448044309 | Putnam Pub Group, June 1, 1968, cover price $8.95 | About this edition: A guide for parents who want to be able to answer their children's endless questions

9780448044309 | Putnam Pub Group, June 1, 1968, cover price $8.95 | About this edition: A guide for parents who want to be able to answer their children's endless questions

9780448044866 | Gift edition (Putnam Pub Group, June 1, 1965), cover price $23.85 | also contains Outsmarting Alzheimer's: What You Could Do to Reduce Your Risk