1. Two new plant genera of Pennsylvanian age from Kansas coal balls Author/Creator: Mamay, Sergius H., 1920- Publication/Creation: Washington : U.S. Govt. Print. Off, 1954 Resource Type: Book Is Part Of: U.S. Geological Survey professional paper, no. 254. Access & Availability: Loading
2. Two new plant genera of Pennsylvanian age from Kansas coal balls Author/Creator: Mamay, Sergius H., 1920- author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1954 Resource Type: Book Access & Availability: Loading