The geology and physiography of the Mammoth Cave national park,
by Armin Kohl Lobeck. Illustrated with thirty-nine photographs, maps, and diagrams.
- Frankfort, Ky., The Kentucky Geological survey, 1928.
- 7 p. l., 69 p. incl. front., illus., maps, diagrs. 23 cm.
- Kentucky. Geological survey. Ser. VI. Pamphlet XXI .