Use databases to find articles. You can search a database by key words, by author, by journal name and other ways depending on where you are starting and what you need to find.
Information on women in politics may be found in both the Political Science and Women's & Gender Studies literature, as well as other disciplines, depending on your topic. Because of this interdisciplinary nature, there may be many choices for research on your topic of interest. Here are some databases that cover CORE journals:
Google Scholar may also be useful for your research (search box on the upper left). The advantage is that it is extremely broad and interdisciplinary. The disadvantage is that the results can be chaotic and hard to control. Think of Google Scholar not as a replacement for but rather a complement to the libraries' databases.
There are many other library databases that might be of use depending on the focus of your topic. If you are looking at issues related to health, education, history, or government policy aspects, for instance, you will want to take a look at other subject areas. All of these categories have their own specialized, core databases. To get to these other databases, go to the MU Libraries home page, click on the gold tab, Databases, and then Databases by Subject. You will see that there are lots of other possibilities such as Health & Medicine, Education, and Government & Law.