His scientific work appeared mainly in journal articles , written in German ; it became widely known to English-speaking scientists through its description in Tinbergen 's 1951 book `` The Study of Instinct '' , though many of his papers were later published in English translation in the two volumes titled `` Studies in Animal and Human Behavior '' .
His scientific work appeared mainly in journal articles , written in German ; they became widely known to English-speaking scientists through the descriptions of it in Tinbergen 's 1951 book `` The study of instinct '' , though many of his papers were later published in English translation in the two volumes titled `` Studies in animal and human behaviour '' .