Phoronida

included taxa and references - Tree of Life

species classification - University of Michigan Museum of Zoology

list of the numbers of taxa described - Texas A&M University

ITIS - taxonomy and nomenclatural information - Integrated Taxonomic Information System

taxonomic hierarchy - The Taxonomicon

IRMNG genera list

searchable database of taxa

overview, lab exercise, part of online Invertebrate Anatomy course

online pdf article - Invertebrate Zoology

online pdf article, Invertebrate Zoology