Yes - as a university professor, I can say with some certainty that it will. Failing to cite sources is a form of plagiarism. Not citing correctly could also be considered plagiarism, depending on what you mean by that - simply getting the date, name, title, etc in an order other than the one your institution requires will not have too big an impact, but not having the date, name, title or page numbers correct, if caught, will have a huge impact.