Rothwell, G. W.; Stockey, R. A. (2013). Evolution and phylogeny of gnetophytes: evidence from the anatomically preserved seed cone Protoephedrites eamesii gen. et sp. nov. and the seeds of several bennettitalean species. International Journal of Plant Sciences. 174(3): 511-529.
Evolution and phylogeny of gnetophytes: evidence from the anatomically preserved seed cone Protoephedrites eamesii gen. et sp. nov. and the seeds of several bennettitalean species