2016, Health Effect of Forest Bathing Trip on Elderly Patients with Chronic Obstructive Pulmonary Disease 28. April 2020 Jia BB, Yang ZX, Mao GX, Lyu YD, Wen XL, Xu WH, Lyu XL, Cao YB, Wang GF Biomed Environ Sci. 2016 Mar;29(3):212-8 https://www.ncbi.nlm.nih.gov/pubmed/27109132