At University you should be using peer reviewed journal articles.
You will need to find academic articles for your assignments. If you are not sure about an article you are looking at, its a good idea to check whether the journal is peer reviewed. If the journal is peer reviewed you can be confident that the article is academic. The information sheet on this page shows you how to do this on the Ulrichsweb directory.
You can also access the How to Guide here
Refer to this example to see some of the features you need to look for in an Academic paper.