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.
Rothman KJ, Glass RL, Espinal F, Velez H. Caries-free teeth in the absence of fluoride ion. J Public Health Dent. 1972;32(4):225-8. doi: 10.1111/j.1752-7325.1972.tb03977.x