HarperCollins Children’s Books has announced the fall 2011 release of a collection of never-before published Shel Silverstein poems and illustrations. Not yet titled, the book will share the same format as the late author’s previous poetry collections: Where the Sidewalk Ends, A Light in the Attic, and Falling Up. These and other children’s books by Silverstein, who died in 1999, have sold more than 25 million hardcover copies in the U.S. alone and have been translated into more than 30 languages.