Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment. - Wiebers,D.O.; Whisnant,J.P.; Huston,J.; Meissner,I.; Brown,R.D.; Piepgras,D.G.; Forbes,G.S.; Thielen,K.; Nichols,D.; O'Fallon,W.M.; Peacock,J.; Jaeger,L.; et al. (Lancet, 2003)