Atmospheric composition 1 million years ago from blue ice in the Allan Hills, Antarctica.

MLA

Higgins, John A., et al. “Atmospheric Composition 1 Million Years Ago from Blue Ice in the Allan Hills, Antarctica.” Proceedings of the National Academy of Sciences of the United States of America, vol. 112, no. 22, June 2015, pp. 6887–91. EBSCOhost, https://doi.org/10.1073/pnas.1420232112.

APA

Higgins, J. A., Kurbatov, A. V., Spaulding, N. E., Brook, E., Introne, D. S., Chimiak, L. M., Yan, Y., Mayewski, P. A., & Bender, M. L. (2015). Atmospheric composition 1 million years ago from blue ice in the Allan Hills, Antarctica. Proceedings of the National Academy of Sciences of the United States of America, 112(22), 6887–6891. https://doi.org/10.1073/pnas.1420232112

Chicago

Higgins, John A, Andrei V Kurbatov, Nicole E Spaulding, Ed Brook, Douglas S Introne, Laura M Chimiak, Yuzhen Yan, Paul A Mayewski, and Michael L Bender. 2015. “Atmospheric Composition 1 Million Years Ago from Blue Ice in the Allan Hills, Antarctica.” Proceedings of the National Academy of Sciences of the United States of America 112 (22): 6887–91. doi:10.1073/pnas.1420232112.