APA   Click to copy
Elwood Madden, M. E., Bodnar, R. J., & Rimstidt, J. D. (2004). Jarosite as an indicator of water-limited chemical weathering on Mars. Nature, 431, 821–823.

Chicago/Turabian   Click to copy
Elwood Madden, ME, RJ Bodnar, and JD Rimstidt. “Jarosite as an Indicator of Water-Limited Chemical Weathering on Mars.” Nature 431 (2004): 821–823.

MLA   Click to copy
Elwood Madden, M. E., et al. “Jarosite as an Indicator of Water-Limited Chemical Weathering on Mars.” Nature, vol. 431, Nature Publishing Group UK London, 2004, pp. 821–23.

@article{elwood2004a,
  title = {Jarosite as an indicator of water-limited chemical weathering on Mars},
  year = {2004},
  journal = {Nature},
  pages = {821--823},
  publisher = {Nature Publishing Group UK London},
  volume = {431},
  author = {Elwood Madden, ME and Bodnar, RJ and Rimstidt, JD}
}