Conifer ovulate cones accumulate pollen principally by simple impaction.

MLA

Cresswell, James E., et al. “Conifer Ovulate Cones Accumulate Pollen Principally by Simple Impaction.” Proceedings of the National Academy of Sciences of the United States of America, vol. 104, no. 46, Nov. 2007, pp. 18141–44. EBSCOhost, https://doi.org/10.1073/pnas.0706434104.

APA

Cresswell, J. E., Henning, K., Pennel, C., Lahoubi, M., Patrick, M. A., Young, P. G., & Tabor, G. R. (2007). Conifer ovulate cones accumulate pollen principally by simple impaction. Proceedings of the National Academy of Sciences of the United States of America, 104(46), 18141–18144. https://doi.org/10.1073/pnas.0706434104

Chicago

Cresswell, James E, Kevin Henning, Christophe Pennel, Mohamed Lahoubi, Michael A Patrick, Phillipe G Young, and Gavin R Tabor. 2007. “Conifer Ovulate Cones Accumulate Pollen Principally by Simple Impaction.” Proceedings of the National Academy of Sciences of the United States of America 104 (46): 18141–44. doi:10.1073/pnas.0706434104.