Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) FRONTERA WR,A cross-sectional study of muscle strength and mass in 45- to 78-yr-old men and women,J. Appl. Physiol.,,,1991,71,,644-650,https://cir.nii.ac.jp/crid/1570291225231178112,