Aguado J, Campbell A, Ascaso C, Navarro P, Garcia-Esteve L, Luciano JV. Examining the factor structure and discriminant validity of the 12-Item General Health Questionnaire (GHQ-12) among Spanish postpartum women. Assessment. 2012 Dec 19;19(4):517-25.
Scotland GS, Philip S, Fleming AD, Goatman KA, Sharp PF, McNamee P, Fonseca S, Prescott G, Olson JA. Manual versus automated: the diabetic retinopathy screening debate. OTE. 2008 Jan 1;4(2):14-6.
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