TY - RPRT TI - Shelf and open-ocean calcareous phytoplankton assemblages across the Paleocene-Eocene thermal maximum: Implications for global productivity gradients AU - S.J. Gibbs AU - T.J. Bralower AU - Paul R. Bown AU - J.C. Zachos AU - L. M. Bybell PY - 2006 DO - 10.1130/g22381.1 UR - https://pubs.usgs.gov/publication/70030249 ID - 70030249 ER -