A sequence of ten records of the directional wave spectrum has been obtained from the motions of a floating buoy located at 56° 45'N, 18° 57'W. The records were taken to check the results derived from a numerical scheme for forecasting ocean waves in the North Atlantic....
Ewing, J. A.. 1969. "Some measurements of the directional wave spectrum." Journal of Marine Research 27, (2). https://elischolar.library.yale.edu/journal_of_marine_research/1150