Birch, H S, Coxall, H K, Pearson, P N, Kroon, D & Schmidt, D N 2016, ' Partial collapse of the marine carbon pump after the Cretaceous-Paleogene boundary ', Geology, vol. 44, no. 4, pp. 287–290 . https://doi.org/10.1130/G37581.1 Birch, H S, Coxall, H K, Pearson, P N, Kroon, D & Schmidt, D N 2016, ' Partial collapse of the marine carbon pump after the Cretaceous-Paleogene boundary ', Geology, vol. 44, no. 4, G37581, pp. 287-290 . https://doi.org/10.1130/G37581.1