Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) 坪田 敏男 and Garshelis David L and Nelson Ralph A,Theriogenology:Sex steroid and prolactin profiles in male American black bears(Ursus americanus)during denning,The journal of veterinary medical science = 日本獣醫學会会誌,09167250,東京 : 日本獣医学会,1999-01,61,1,81-83,https://cir.nii.ac.jp/crid/1520572360447916416,