Hydrophone -- History -- 20th century. / https://id.loc.gov/authorities/subjects/sh85063482 https://id.loc.gov/authorities/subjects/sh2002006165 : Manstan, Roy R.,
Hydrotherapy -- United States -- History -- 19th century. / https://id.loc.gov/authorities/subjects/sh85063494 https://id.loc.gov/authorities/names/n78095330-781 https://id.loc.gov/authorities/subjects/sh2002006167 : Cayleff, Susan E.,