1. A. M. Terrés-Speziale, Rev Mex Patol Clin 53(1), pp. 29–38 (2006).
2. Negatively-charged air conditions and responses of the human psycho-neuro-endocrino-immune network
3. Air ions: Past problems and future directions
4. The calming effects of negative air ions on manic patients: A pilot study
5. T. Otsuki, K. Takahashi, A. Mase, T. Kawado, M. Kotani, M.Maeda, S. Murakami, N. Kumagai, H. Hayashi, Y. Chen, Y. Nishimura, Y. Miura, T. Shirahama, M. Yoshimatsu, K. Morimoto, Kawasaki Medical Journal 35(3), pp. 205–214 (2009).