Grimm, E.C. 2001. Trends and palaeoecological problems in the vegetation and climate history of the northern Great Plains, U.S.A. Biology and Environment: Proceedings of the Royal Irish Academy. 101B(1/2): 47-64.

Grimm, E.C. 2001. Trends and palaeoecological problems in the vegetation and climate history of the northern Great Plains, U.S.A. Biology and Environment: Proceedings of the Royal Irish Academy. 101B(1/2): 47-64.