A geological account of the Unionville Serpentine (Corundum Hill region) Read more about A geological account of the Unionville Serpentine (Corundum Hill region)
Letter of February 4, 1970, to Robin Hart at West Chester State College Read more about Letter of February 4, 1970, to Robin Hart at West Chester State College
A study of seepage wetlands in Pennsylvania Read more about A study of seepage wetlands in Pennsylvania
Savannas, Barrens, and Rock Outcrop Plant Communities of North America Read more about Savannas, Barrens, and Rock Outcrop Plant Communities of North America
Checklist of the moths of the Goat Hill, Rock Springs and New Texas serpentine barrens Read more about Checklist of the moths of the Goat Hill, Rock Springs and New Texas serpentine barrens