Barrington, E. J. W. (1965). The biology of Hemichordata and Protochordata. W. H. Freeman.
Lua i Stíl Chicago (17ú heag.)Barrington, E. J. W. The Biology of Hemichordata and Protochordata. San Francisco: W. H. Freeman, 1965.
Lua MLA (9ú heag.)Barrington, E. J. W. The Biology of Hemichordata and Protochordata. W. H. Freeman, 1965.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.