Google Scholar is an open source search tool that spans across many disciplines and sources: it is often a very good resource for finding materials that may not appear in subscription library databases such as reports from professional societies, preprint repositories, universities, research institutes and think tanks, and other scholarly organizations.
Databases allow you to search many journals at once. Here, you can search journals one by one. This may be useful if you have already found out that a particular journal publishes a lot on your topic, or if you know there is a special issue on your topic. You may also access all these e-journals and more through the Hunter College Libraries website's E-Journal Look Up