Common variants conferring risk of schizophrenia - Stefansson,H; Ophoff,RA; Steinberg,S; Andreassen,OA; Cichon,S; Rujescu,D; Werge,T; Pietilainen,OPH; Mors,O; Mortensen,PB; Sigurdsson,E; Gustafsson,O; et al. (NATURE, 2009)