Use keyword searching in relevant databases. Brainstorm different keywords for your topic and see what happens.
Use Boolean searching (AND, OR, NOT) to expand or narrow your searches.
Use the drop-down boxes in the database's Advanced Search to help you narrow or expand your search.
When you find a relevant item, click on the record and look for subject terms. Clicking on a subject term will bring up other related items.
Try your keywords and subject terms in other databases, and see what you find!