School grades, parental education and suicide—a national register-based cohort study
Charlotte Björkenstam, Gunilla Ringbäck Weitoft, Anders Hjern, Peter Nordström, Johan Hallqvist, Rickard Ljung
J Epidemiol Community Health Nov 2011, 65 (11) 993-998; DOI: 10.1136/jech.2010.117226