American fern journal - American Fern Society. (American Fern Society, 1980)

The Fern gazette - British Pteridological Society. (British Pteridological Society, 2002)

The Fern gazette - British Pteridological Society. (British Pteridological Society, 2002)

The Fern gazette - British Pteridological Society. (British Pteridological Society, 2002)

Illinois Natural History Survey bulletin - Illinois. Natural History Survey Division (The Survey, 1987)