I recently submitted an assignment but realised a week later that one of the sources I have used in the essay and bibliography was wrong. I'm not sure how it happened I'm guessing some mix up with the citation software I used but I'm really scared that my professor will be able to tell. Does anybody know how thoroughly lecturers check the references used?
It's a mistake in good faith. You are a student, so you're supposed to learn. It's great that you found it yourself. Just send the lecturer an email explaining what happened. He probably won't really mind, but if the bibliography is included in the grade (e.g. if this is an Academic Writing course or so) he might deduct some point.