Mangel AW, Fehnel SE. End points in irritable bowel syndrome. Expert Rev Gastroenterol Hepatol. 2011 Jun 1;5(3):293-5.
Küçükdeveci AA, McKenna SP, Kutlay S, Gürsel Y, Whalley D, Arasýl T. The development and psychometric assessment of the Turkish version of the Nottingham Health Profile. Int J Rehabil Res. 2000 Mar 1;23(1):31-8.