It was based on Grolier’s older Book of Knowledge. The New Book of Knowledge was originally published by Grolier in the 1940s. Currently published by Scholastic Press, it has gone through several editions. The 2007 edition is published in 21 volumes and contains more than 9,000 articles. By an agreement with Scholastic, Grolier published the contents of the encyclopedia online with registration. In 2000, Scholastic Corporation acquired Grolier and now has full rights to the contents of The New Book of Knowledge. In 2005 there was an Internet petition to reinclude an article on Ancient Persia in the encyclopedia, which was omitted from the 2005 edition. In response, Scholastic restored the article in the 2006 edition.