Increased prefrontal and hippocampal glutamate concentration in schizophrenia: Evidence from a magnetic resonance spectroscopy study - Tebartz van Elst, L; Valerius, G; Büchert, M; Thiel, T; Rüsch, N; Bubl, E; Henning, J; Ebert, D; Olbrich, HM (Biol Psychiatry, 2005)