This 20-volume set is written by more than 5,000 international leaders in science and technology, including 35 Nobel Prize laureates, all selected and invited to contribute by McGraw-Hill's board of consulting editors. Readers will find over 7,000 articles covering nearly 100 fields of science, more than 1,700 new and updated articles, and 12,000 illustrations. The encyclopedia spans 97 subject areas, covering major disciplines in science and technology.