RATCLIFFE N (1995) Nederlandse Ornithologische Unie: Themadag Seabirds at sea in the North Sea: Environmental determinants of the distribution of small cetaceans in the waters of North-west Europe. LIMOSA 68 (3): 124-124.

Nederlandse Ornithologische Unie: Themadag Seabirds at sea in the North Sea: Environmental determinants of the distribution of small cetaceans in the waters of North-west Europe

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