You should send a cover letter only if your employers ask for it. If employers specify that they expect a résumé and references from you but do not mention the cover letter, leave the cover letter out. But if, on the other hand, they state that applicants should send them the cover letter, a failure to do so may disqualify you as a potential candidate for the position. By not sending your cover letter, you will also lose a good opportunity to tell your employers about yourself in a more personal tone. Remember that the résumé states dry facts. Even though it says a lot about your education and work experience, it does not reveal your personality. In your cover letter, by contrast, you can write about your ideology, career objectives, drives, and hobbies and, in so doing, draw a more personal self-portrait that may impress your recruiters more than dry facts about the places where you worked.