Additional attachments to internship application?

<p>I am applying to this biomedical engineering company online, and the only requirements are a resume and a cover letter. However, there is room for additional attachments, which it suggests previously published/submitted works as examples. However, I don’t have any of these. I was wondering it it is appropriate to have a professor write me a reference letter from a class that is relevant to the job I am applying for. Do I ask him to send it to me, then I can attach it myself? I’m wondering how it would work. I really want to add something extra to increase my chances. </p>