Effects of Yoga Versus Walking on Mood, Anxiety, and Brain GABA Levels: A Randomized Controlled MRS Study. - Streeter CC; Whitfield TH; Owen L; Rein T; Karri SK; Yakhkind A; Perlmutter R; Prescot A; Renshaw PF; Ciraulo DA; Jensen JE (Journal of Alternative & Complementary Medicine, 2010)