Wang, X. T., Sigman, D. M., Prokopenko, M. G., Adkins, J. F., Robinson, L. F., Hines, S. K., Chai, J., Studer, A. S., Martinez-Garcia,
A., Chen, T., & Haug, G. H. (2017). Deep-sea coral evidence for lower Southern
Ocean surface nitrate concentrations during the last ice age. Proceedings of the National Academy
of Sciences of the United States of America, 114(13), 3352-3357. doi:10.1073/pnas.1615718114.