Dude,
If you are good enough, they will call you up. So, quit thinking about whether you need a reference or not. Rather spend time on improving your resume quality. Make sure you have the keywords for the job you need. Highlight your ability to work in groups (if it so desires), leadership ability (in every job) and most of all, your accomplishments. Show that you can do something concrete and how that may help you contribute positively to the firm's growth. And, oh yea, try to make your resume as short as possible. People do not have time to go over pages and pages unless its some technical stuff that you cannot fit in a page. And, as someone said earlier, business resumes are shorter than those geared towards science jobs.

The question I always like: Why should we hire you and not someone equally qualified from another reputed institution? What makes you different?