Google Scholar Again
Also I found out that Google Scholar will break some boundaries that inhibit interdisciplinary use of scholarly articles. For example we librarians and information scientists usually search LISA or ISA for our research purposes and think that they suffice us. But if you do your search in Google Scholar as well, you might found (as I did) some very useful and pertinent materials in the other areas like computer science or in some general resources Like the Science Magazine that we usually never check. I feel that Google Scholar works like a Federated Search Engine!