Pauly-Wissowa, Realencyclopädie der classischen Altertumswissenschaft, 1894ff, is an encyclopedia of classical scholarship. With its supplements it comprises well over a hundred volumes.
Each article was written by a recognized specialist in the relevant field.
The index to Pauly-Wissowa is available on CD-ROM.
... out with 26.0% under the age of 18, 9.4% from 18 to 24, 34.6% from 25 to 44, 19.4% from 45 to 64, and 10.6% who are 65 years of age or older. The median age is 34 ...