1. Trinchieri A: Epidemiology of urolithiasis: an update. Clin Cases Miner Bone Metab. 2008, 5 (2): 101-106.
2. Ahmed A, Saeed NM: Experience with the management of urethral stones presenting with urinary retention at Gusau. Niger J Clin Pract. 2008, 11 (4): 309-311.
3. Adetayo FO, Saanu OO, Osegbe DN: Chemical composition of urinary calculi in Nigerians. NQJHM. 2004, 14 (2): 143-146.
4. Khai Linh VH, Segura JW: Lower urinary tract calculi. Campbell's urology. Volume 3. Edited by: Wein AJ, Kavoussi LR, Novick AC. 2007, St. Louis MO: Saunders Elsevier, 2663-2673. 9
5. Bielawska H, Epstein NL: A stone below: a urethral stone causing acute urinary retention and renal failure. Case report. CJEM. 2010, 12 (4): 371-380.