• A comparison between two sonic measuring systems for demersal fish 

      Dowd, R. G.; Bakken, Erling; Nakken, Odd (Peer reviewed; Journal article, 1970)
      Two sonic methods for estimation of abundance of fish stocks, the echo integrator and the digital counter methods, were compared on single and schooling fish in the Lofoten area of Norway during March 1969. Good correlation ...