Echo Sounding devices presented by the Marconi Sounding Device Company during the IVth International Hydrographic Conference Monaco, 1937 — Marconi Echometer, types 421, 424, 429, 430, Marconi Magneto Striction Equipment, with recorder. IHR [Internet]. 2018 May 30 [cited 2024 Dec. 21];(2). Available from: https://journals.lib.unb.ca/index.php/ihr/article/view/27634