Professors will tell you this is not true, but I know it is. If you want a paper to score well, cite more than the number of articles and books you’re supposed to cite for the assignment. This is an example of ‘exceeding expectations’, so it’s hard for them to not give you an A.
Do you know about citation tools that automatically generate a reference list for you? So it’s easy to gather a lot of citations and make a nice ref list/bibliography page. List as many resources as possible (mindful of sufficient relevance), and to use this combination to create an effective list of articles/books relevant to the course.
Many professors say they want to see a lot of evidence of understanding, with critical analysis – but only their most talented students achieve that. When you get right down to brass tacks, it’s hard for them to give you a low grade when you cite more than the required number of articles/books.