The first edition (1949–1968, suppl. 1973–1986) comprises 17 volumes, of which two are supplement volumes, and one is an index or Register. The current second edition (1994–2007, suppl. 2008) consists of a subject encyclopedia (Sachteil) in 10 volumes (including the index or Register) and a biographical encyclopedia (Personenteil) in 17 volumes and an index or Register volume. An additional supplement volume, addressing both subjects and personages, was published in May, 2008. A CD-Rom version of the second edition is also available in a few libraries, mainly in Germany.