Contains more than 25,500 entries written by 100 expert contributors, 1,200 illustrations, 30 picture essays and 18 maps. It is unique in being the only general encyclopedia to be updated every year. This year over 2,000 entries were revised to take account of among other things the changes in Russia, Yugoslavia and Czechoslovakia. There are also many new biographies including Andre Agassi, Boutros Ghali, Bill Clinton, Jacques Dolors and Jacques Derida. The encyclopedia is particularly strong on science and technology, with picture essays and full page illustrations explaining colour photography and the internal combustion engine, for example, but it also contains a whole library of facts on the countries of the world, history, natural history, medicine and technology, sports, singers, theatre and literature and much more.