1985, Observations on the effect of immersion in Bath spa water

J P O'Hare, A Heywood, C Summerhayes, G Lunn, J M Evans, G Walters, R J Corrall, and P A Dieppe

Br Med J (Clin Res Ed). 1985 Dec 21; 291(6511): 1747–1751

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1419186/