Erik Hammerstad, Stein Åsheim, Kjell Nilsen, Helge Bodholt; Advances in multibeam echo sounder technology, Proceedings of IEEE OCEANS'93 Conference, pp. 482 - 487, October 1993.

Eric Hammerstad, Freddy Pøhner, Francois Parthiot, John Bennett; Field Testing of a New Deep Water Multibeam Echo Sounder, Proceedings of IEEE OCEANS'91 Conference, pp. 743 - 749, October 1991.

Erik Hammerstad, Freddy Pøhner; Ultra wide swath deep sea interferometric multibeam echo sounder with sea bottom imaging system, Proceedings of IEEE OCEANS'90 Conference, pp. 63 - 68, September 1990.

Erik Hammerstad, Arne Løvik, Svein Minde, Leif Krane, Magne Steinset; Field Performance of the Benigraph High-Resolution Multibeam Seafloor Mapping System, Proceedings of MTS/IEEE OCEANS'85 Conference, pp. 682 - 685, November 1985.