@misc{Darwin_Charles_Robert_(1809–1882)_The_1904,
 author={Darwin, Charles Robert (1809–1882)},
 volume={Vol. 6-7},
 copyright={Public Domain},
 address={New York},
 journal={The New Science Library},
 howpublished={online},
 year={1904},
 publisher={J. A. Hill and Co.},
 title={The descent of man and selection in relation to sex. Vol. 1-2},
}