2018, Spa therapy (balneotherapy) relieves mental stress, sleep disorder, and general health problems in sub-healthy people

Yang B, Qin QZ, Han LL, Lin J, Chen Y

Int J Biometeorol. 2018 Feb;62(2):261-272. doi: 10.1007/s00484-017-1447-5. Epub 2017 Sep 21

https://www.ncbi.nlm.nih.gov/pubmed/28936572