American fern journal - American Fern Society. (American Fern Society, 1984)

American fern journal - American Fern Society. (American Fern Society, 1984)

American fern journal - American Fern Society. (American Fern Society, 2003)

American fern journal - American Fern Society. (American Fern Society, 2003)

Fieldiana Botany - Field Museum of Natural History. (Chicago Natural History Museum, 1994)