Rocks & Minerals

Fossil Forests of the Yellowstone National Park

The Geologic Story of Palo Duro Canyon

The Geology of D.A.R. State Park, Mt. Philo State Forest Park, Sand Bar State Park

British Museum (Natural History) General Guide

Gems in the Smithsonian Institution

Cave Regions of the Ozarks and Black Hills

Underground Treasures: How and Where to Find Them

The Geology of Groton State Forest

Across Mongolian Plains

Underground Treasures: How and Where to Find Them

Pleistocene Bats from San Josecito Cave, Nuevo Leon, Mexico

The Glaciers of the Alps

Walks and Talks in the Geological Field

A Short History of the Academy of Natural Sciences of Philadelphia

Devils Tower National Monument

The Ornithosauria

Fragments of Earth Lore: Sketches & Addresses Geological and Geographical

Biology, The Myth Of Evolution