BioStor
 | Vegetation on bauxitic soils in Jamaica, II R A Howard and G R Proctor (1957) Journal of the Arnold Arboretum 38: 151-169 |
 | The Enumeratio and Selectarum of Nicolaus Von Jacquin R A Howard (1973) Journal of the Arnold Arboretum 54: 435-470 |
 | Solanum and Its Close Relatives in Florida W G D'arcy (1974) Annals of the Missouri Botanical Garden 61: 819-867 |