If you are already on a category page or a long list of titles, use your browser's built-in "Find" function: Press Ctrl+F (Windows) or Cmd+F (Mac).
Most files are user-uploaded, meaning there is no official copyright or quality verification.
Since the on-site search can be finicky or hidden, the most reliable method is to let Google index the site for you. This bypasses the need for an on-site search bar entirely.