Extinction is forever : threatened and endangered species of plants in the Americas and their significance in ecosystems today and in the future : proceedings of a symposium held at the New York Botanical Garden, May 11-13, 1976, in commemoration of the Bicentennial of the United States of America - Prance, Ghillean Iain Tolmie 1937-; Elias, Thomas S. 1942- (The New York Botanical Garden, 1977)
Reimpresiones: 1978