McGuire MK, Nunn ME: Prognosis versus actual outcome. II. The effectiveness of clinical parameters in developing an accurate prognosis. J Periodontol, 67: 658-665, 1996.
Kwok V, Caton JG: Commentary: prognosis revisited: a system for assigning periodontal prognosis. J Periodontol, 78: 2063-2071, 2007.
McGuire MK, Nunn ME: Prognosis versus actual outcome. III. The effectiveness of clinical parameters in accurately predicting tooth survival. J Periodontol, 67: 666-674, 1996.