Initially a textbook publisher, they added journal publishing in the 1970s, and encyclopedia publishing in the early 1980s. They were purchased by Taylor and Francis in 2003. At that time, they published 78 journals and 300 new books annually. As of 2008, they have a total of 26 encyclopedias available. These encyclopedias deal with scientific issues such as agricultural engineering, chemistry, agronomy, and library science.