Mamoon, Nadira, et al. “UROTHELIAL NEOPLASIA OF THE URINARY BLADDER - COMPARISON OF INTEROBSERVER VARIABILITY FOR WHO CLASSIFICATION 1972 WITH WHO ISUP CONSENSUS CLASSIFICATION 1998”. Journal of Ayub Medical College Abbottabad, vol. 18, no. 2, Apr. 2006, pp. 4-8, https://jamc.ayubmed.edu.pk/index.php/jamc/article/view/4974.