You can choose to only search for full-text versions of articles in many databases, such as ProQuest or PsycINFO but don't limit yourself! There is another way to see if the library has your article in a full-text, online version.
MGetIt is a tool provided by the University Library that allows library databases to "talk to each other" in order to find on-line versions of articles. If you find an article citation listed in ProQuest, for example but don't see a full-text version of the article, look for an MGet It icon, like the one above. Clicking on this icon will show you if the library has the article available online from a database other than ProQuest. Sometimes there may be several links to on-line version available.
Here are two citations from ProQuest. The first one has an MGetIt icon because full-text is not available from ProQuest. The second citation has full-text available and so does not have this icon.
Try Google Scholar with MGet It links. Google Scholar may not show the MGet It icon but look for a link that says "Availability at UMichigan." This works the same way as MGet It.
The current on-duty librarian for the library-wide Ask a Librarian IM service is available when you see a green dot at the top of the box.
See http://www.lib.umich.edu/ask for additional contact methods.