1. Bidens pilosa complex (Asteraceae) in North and Central America;Ballard;American Journal of Botany,1986
2. Index to plant chromosome numbers 1975-1978;Monographs in Systematic Botany from the Missouri Botanical Garden,1981
3. Index to plant chromosome numbers 1979-1981;Monographs in Systematic Botany from the Missouri Botanical Garden,1984
4. Index to plant chromosome numbers 1982-1983;Monographs in Systematic Botany from the Missouri Botanical Garden,1985