Old Age: The results of information received respecting nearly nine hundred persons who had attained the age of eighty years, including seventy-four centenarians. By George Murray Humphry, M.D., F.R.S. Cambridge: Macmillan and Bowes, 1889
"Old Age: The results of information received respecting nearly nine hundred persons who had attained the age of eighty years, including seventy-four centenarians. By George Murray Humphry, M.D., F.R.S. Cambridge: Macmillan and Bowes, 1889." Journal of Mental Science 36.153 (1890) 257-259