Garcia-Esteve L, Navarro P, Ascaso C, Torres A, Aguado J, Gelabert E, Martin-Santos R. Family caregiver role and premenstrual syndrome as associated factors for postnatal depression. Arch Womens Ment Health. 2008 Jul;11(3):193-200.
Michels KB, Rothman KJ. Update on unethical use of placebos in randomised trials. Bioethics. 2003 Apr;17(2):188-204.