R. J.  Soreng, Davis, J. I., and Voionmaa, M. A., ?A phylogenetic analysis of Poaceae, tribe Poeae sensu lato based on morphological characters and sequence data from three plastid-encoded genes: evidence for reticulation, and a new classification for the tribe?, Kew Bull, vol. 62, no. 3, pp. 425 - 454, 2007.