Pre-Columbian plant migration

by Pre-Columbian Plant Migration Symposium (1982 Manchester, England), Robert McK. Bird, Richard I. Ford, Jorge Leon, Barbara Pickersgill, Timothy Plowman, Prance, Ghillean T., Anna Roosevelt, Richard Evans Schultes, Paul R. Bloom, Helen Sorayya Carr, Edward S., Jr. Deevey, S.E. Garrett-Jones, Nancy L. Hamblin, Hattula Moholy-Nagy, Amadeo M. Rea, Prudence M. Rice, Julie Stein, B.L., II Turner, Hague H. Vaughan, Richard R. Wilk, Frederick Matthew Wiseman