1. Coping with the epiphytic existence, pollination strategies;Ackerman;Selbyana,1986
2. Patterns and maintenance of extraordinary variation in the Caribbean orchid Tolumnia (Oncidiurri);Ackerman;variegata. Systematic Botany,1991
3. Epiphyte host specificity of Encyclia krugii, a Puerto Rican endemic orchid;Ackerman;Lindleyana,1989
4. Reproductive biology of Oncidium variegatum: moon phases, pollination and fruit set;Ackerman;American Orchid Society Bulletin,1985
5. Escape from disease;Agrios,1980