Oliver, W. A. (1964). The devonian colonial coral genus Billingsastraea and its earliest known species: The geographic and stratigraphic distribution of Billingsastraea with a redescription of B. affinis its earliest known species. U.S. Gov. Print. Off.
Chicago-Zitierstil (17. Ausg.)Oliver, William A. The Devonian Colonial Coral Genus Billingsastraea and Its Earliest Known Species: The Geographic and Stratigraphic Distribution of Billingsastraea with a Redescription of B. Affinis Its Earliest Known Species. Washington, D.C: U.S. Gov. Print. Off, 1964.
MLA-Zitierstil (9. Ausg.)Oliver, William A. The Devonian Colonial Coral Genus Billingsastraea and Its Earliest Known Species: The Geographic and Stratigraphic Distribution of Billingsastraea with a Redescription of B. Affinis Its Earliest Known Species. U.S. Gov. Print. Off, 1964.