One method of locating material for your assignment is to start by studying a standard survey instrument. You can then search for journal articles that used that instrument in their research.
When a researcher uses a standard test or instrument in their research, they'll cite it. Find a test or instrument that speaks to your topic, then go to our journal databases to search for it in quotes to discover articles which used that instrument in their research.
For example, if I searched for mathematics in the "PsycTests" databases, I would find out about the "Individual Interest in Mathematics Assessment".
Then, I'd head over to "PsycInfo" database, and search for that assessment (in quotes) to find an article based on the test.
Having trouble finding a specific instrument? Contact me! I have some sneaky ways to find the full text of instruments...