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.
... under the age of 18 living with them, 44.2% are married couples living together, 12.2% have a female householder with no husband present, and 39.0% are non-families ...