APA   Click to copy
Colwell, R. K. (1982). Female-biased sex ratios (reply). Nature, 298, 495–496.

Chicago/Turabian   Click to copy
Colwell, Robert K. “Female-Biased Sex Ratios (Reply).” Nature 298 (1982): 495–496.

MLA   Click to copy
Colwell, Robert K. “Female-Biased Sex Ratios (Reply).” Nature, vol. 298, Nature Publishing Group, 1982, pp. 495–96.

@article{colwell1982a,
  title = {Female-biased sex ratios (reply)},
  year = {1982},
  journal = {Nature},
  pages = {495--496},
  publisher = {Nature Publishing Group},
  volume = {298},
  author = {Colwell, Robert K}
}