DiTrapani J, Rockwood N, Jeon M. Explanatory IRT analysis using the SPIRT macro in SPSS. TQMP. 2018;14(2):81-98. doi: 10.20982/tqmp.14.2.p081
Garcia-Esteve L, Torres A, Navarro P, Aguado J, Ascaso C. Maternidad the planned y psicomorbilidad: un riesgo evitable / Unplanned pregnancy and psychological morbidity: an avoidable risk. Fac Med Barc. 2005 Jul;32(3):111-8.