There is No One Search Engine

Good Possibilities Include

FEDSTATS (http://www.fedstats.gov)

Statistical Resources on the Web (http://www.lib.umich.edu/govdocs/stats.html)

AltaVista (http://altavista.digital.com)
Excite (http://www.excite.com/)

ERIC Clearinghouse (http://ericir.syr.edu/)