1. Percutaneous nephrolithotomy: a routine procedure?;Alken;Br J Urol (Suppl),1983
2. Ultrasonic lithotripsy of renal calculi: a 3-year experience;Marberger;Br J Urol,1983
3. Percutaneous nephrolithotomy results and cost effectiveness;Wickham;Br J Urol,1983
4. Percutaneous lithotripsy;Segura;J Urol,1983
5. Teleskopbougierset zur Perkutanen Nephrostomie;Alken;Aktuel Urol,1981