1. The flora of the Denver and associated formations of Colorado Author/Creator: Knowlton, Frank Hall, 1860-1926, author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1930 Resource Type: Book Access & Availability: Loading
2. Flora of the Montana formation Author/Creator: Knowlton, Frank Hall, 1860-1926, author Publication/Creation: Washington, D.C. : Department of the Interior, United States Geological Survey, 1900 Resource Type: Book Access & Availability: Loading
3. A catalogue of the Cretaceous and Tertiary plants of North America Author/Creator: Knowlton, Frank Hall, 1860-1926, author Publication/Creation: Washington, D.C. : Department of the Interior, United States Geological Survey, 1898 Resource Type: Book Access & Availability: Loading
4. Fossil wood and lignite of the Potomac formation Author/Creator: Knowlton, Frank Hall, 1860-1926, author Publication/Creation: Washington, D.C. : Department of the Interior, United States Geological Survey, 1889 Resource Type: Book Access & Availability: Loading