Very highly regarded after more than 60 years in print. This edition contains a great deal of updated information. Subjects are divided into 12 broad categories covering all the sciences, and the book is heavily cross-referenced for detailed research.
...new and updated articles in every discipline...easy-to-use search engines... (Zentralblatt Math, Vol. 1032, No.7, 2004) "As a source of scientific information it must be rated highly." (Talanta, Vol 52, 2000)