You don't have scholarly works without "scholars"--people who are experts in their field and dedicated to study and advancing knowledge of the subject. Typically they have earned an advanced degree (often a PhD) in their field and work for an organization dedicated to education and research, like a university or sometimes a "think tank." It's always a good idea to "Google" your authors to find out what makes them experts.
Scholars typically publish their research in special "scholarly journals." As young experts in your field, it's important to be exposed to these journals during your studies. Scholarly articles are typically organized in the same basic fashion, which helps make them easier for you to recognize. Scholarly journals are one of three main types of publications, including popular (magazines and newspapers) and trade (for people who work in a specific field).
However, scholars also publish other kinds of works, such as books or even a professional blog or website, that may also be a scholarly/academic source for this assignment.
Any time you look for information on a topic (whether personal or for educational research), you should always evaluate the information.
One way to quickly evaluate the information in front of you is to consider the "3 C's":
Credibility (their expertise makes your paper more authoritative)
You might have also learned about the CRAAP test for evaulating information. That works, too!