Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) WANG MC,"Trends and variations in cervical spine surgery in the United States : medicate beneficiaries, 1992 to 2005",Spine (Phila Pa 1976),,,2009,34,,955-961,https://cir.nii.ac.jp/crid/1571698599225212416,