2007, Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest)–using salivary cortisol and cerebral activity as indicators 22. April 2020 Park BJ, Tsunetsugu Y, Kasetani T, Hirano H, Kagawa T, Sato M, Miyazaki Y. J Physiol Anthropol. 2007 Mar;26(2):123-8 https://www.ncbi.nlm.nih.gov/pubmed/17435354