Don't feel like slogging through a database or three to find a particular article? Look at the citation to see if it includes a DOI: digital object identifier. It's a string of numbers and letters that looks like this: 10.1126/science.1136897.
A DOI works a lot like an ISBN does for a book, identifying a precise document online and ensuring that access to it is stable. Just pop it into the DOI resolver at http://dx.doi.org/ to go straight to the article. Or search for it in Google--nine times out of ten it will get you there in one click.