Kramer, K.U. & Green, P.S. 1990. Volume I. Pteridophytes and Gymnosperms. In K. Kubitzki (ed.), The Families and Genera of Vascular Plants. Springer-Verlag, Berlin/Heidelberg/New York/London/Paris/Tokyo/Hong Kong/Barcelona, [28 Sep] 1990: [I]-[XIII], [1]-404.