Billboard's chart isn't the only one that can't shake Hanson loose.

As “Middle of Nowhere” marks its 38th week on the Billboard Top 200, the wholesome hitmakers also have inspired three books on the New York Times nonfiction paperback best-seller list.

“Hanson: The Official Book” weighs in at No. 9; “Taylor Hanson: Totally Taylor!” sits at No. 12; and the big daddy of them all, “Hanson: MMMBop to the Top,” holds down the 15th spot, after 20 weeks on the list. Waiting backstage for a place on the best-seller stage are other Hanson titles, including “Hanson: The Boys From Nowhere” and “Totally Taylor.” (Yes, a different “Totally Taylor.”)

Two words explain the success of these books: little women. “Hanson are clean-cut kids. They have fun little songs, and they’re attractive to young girls,” says Lisa Clancy, senior editor for Archway Books, which jumped on the Hanson craze by publishing “MMMBop to the Top,” as well as “Taylor Hanson: Totally Taylor!” “Isaac Hanson: Totally Ike!” and, yep, you guessed it, “Zac Hanson: Totally Zac!” “There hasn’t been anything like this since the New Kids on the Block in 1990.”

Most of the Hanson books are unauthorized, which means they’re written with information culled from past interviews, and the band doesn’t see any profits. (Hanson’s reps didn’t return calls for this article.) Even though the books provide few new insights into the group, fans seem happy reading such biographical scraps as “Taylor uses Flex shampoo,” “Zac’s favorite color is blue,” and “Ike wears clear braces.”

As long as the members of Hanson keep revealing their favorite hair care products and fans keep caring, publishers will keep churning out these books as fast as they can be written — which is pretty darned fast. “Our book on Taylor was written in a week, and the Isaac and Zac books took less time,” says Clancy, who is preparing a Hanson trivia book that hits stores on February 10.

To be sure, not all booksellers are fans of the group’s music, but they love catering to those who are. When asked about Hanson, one supervisor at a New York City Barnes & Noble couldn’t stop himself from rolling his eyes as he said, “My fiancée has a 13-year-old daughter.” But he quickly added, “If we sell 500 Hanson books, I’m happy.”