BioStor
 | Studies in the genus Coccoloba, IX. A critique of the South American species [prim.] R A Howard (1960) Journal of the Arnold Arboretum 41: 213-258 |
 | Notes on some plants of Puerto Rico R A Howard (1966) Journal of the Arnold Arboretum 47: 137-146 |
 | Notes on the Piperaceae of the Lesser Antilles R A Howard (1973) Journal of the Arnold Arboretum 54: 377-411 |