Haug , T., K. Tormod Nilssen, N. Øien, and V. Potelov. “Seasonal Distribution of Harp Seals (Phoca Groenlandica) in the Barents Sea”. Polar Research, vol. 13, no. 2, Jan. 1994, pp. 163-72, doi:10.3402/polar.v13i2.6690.