BioStor
 | ∑Miocene fossil woods from the Columbia basalts of Central Washington. J. Arnold Arb. 42: 165--203. U & E S Barghoorn Prakash (1961) Journal of the Arnold Arboretum 42: 165-203 |
 | The Enumeratio and Selectarum of Nicolaus Von Jacquin R A Howard (1973) Journal of the Arnold Arboretum 54: 435-470 |