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.
French M, Neighbors D, Carswell L, Williams R, Bush L. A model for estimating industry compliance costs of food labeling regulations. Agribusiness: An International Journal. 1993;8(2):165-86.