L. Gjersing, J. Caplehorn, and T. Clausen. BMC medical research methodology, 10 (1):
13(January 2010)5507<m:linebreak></m:linebreak>M3: 10.1186/1471-2288-10-13;<m:linebreak></m:linebreak>Validació d'escales.
R. Jaeschke, J. Singer, and G. Guyatt. Controlled clinical trials, 10 (4):
407-15(December 1989)4453<m:linebreak></m:linebreak>LR: 20071115; PUBM: Print; JID: 8006242; ppublish;<m:linebreak></m:linebreak>MDCI.
K. Taylor, R. Margolese, and C. Soskolne. The New England journal of medicine, 310 (21):
1363-7(May 1984)5954<m:linebreak></m:linebreak>LR: 20071115; JID: 0255562; ppublish;<m:linebreak></m:linebreak>Intervenció/placebo.