van der Slot, Margaretha A., et al. “End-Fire Versus Side-Fire: A Randomized Controlled Study of Transrectal Ultrasound Guided Biopsies for Prostate Cancer Detection”. Scandinavian Journal of Urology, vol. 54, no. 2, Mar. 2020, pp. 101-4, doi:10.1080/21681805.2020.1738544.