For earlier coverage in print format only:
Then try any of the following:
The above are some of the most major, general databases. Columbia University Libraries subscribe to many more potentially very useful databases. For complete information on all databases, see http://clio.columbia.edu/databases#
For a more subject-specific approach, try Key Resources for East Asian Studies, which contains listings of both print and online resources, organized by broad subject.
In addition, the following two e-journal collections include many titles relevant to East Asian Studies: