Hedberg H. Hollis. (1961). Part 25: International Subcommission on Stratigraphic Terminology. Stratigraphic Classification and Terminology. 1961.
Chicago-referens (17:e uppl.)Hedberg H. Hollis. Part 25: International Subcommission on Stratigraphic Terminology. Stratigraphic Classification and Terminology. 1961, 1961.
MLA-referens (9:e uppl.)Hedberg H. Hollis. Part 25: International Subcommission on Stratigraphic Terminology. Stratigraphic Classification and Terminology. 1961, 1961.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.