Template:Pigg & Rothwell, 2001
- Pigg, K.B. & Rothwell, G.W. 2001. Anatomically preserved Woodwardia virginica (Blechnaceae) and a new Filicalean fern from the Middle Miocene Yakima Canyon Flora of central Washington, USA. American Journal of Botany 88(5): 777–787. DOI: 10.2307/2657030
