V. A. Grin-Yatsenko, S. Othmer, V. A. Ponomarev, S. A. Evdokimov, Y. Y. Konoplev, and J. D. Kropotov, “Infra-Low Frequency Neurofeedback in Depression: Three case studies”, NR, vol. 5, no. 1, p. 30, Mar. 2018.