2012/1/21 John R. Frank <jrf(a)mit.edu>
verify that they ref'ed the central node before
that date? What about
pages that did ref and no longer do? (probly rare?)
I think this information is not kept explicitely, so the option is brute
force to gather them if you really need. Alternative idea is to get a dump
that is closest to the given date, and use that (but I am not sure that all
the dumps are publicly available backwards).
--
Bináris