* Robson, K.A. 1992. A comparative study of the rare Wenatchee larkspur (''Delphinium viridescens'') and its sympatric relative, Western monkshood (''Aconitum columbianum''). USDA-USFS, Pacific Northwest Research Station, Portland. | * Robson, K.A. 1992. A comparative study of the rare Wenatchee larkspur (''Delphinium viridescens'') and its sympatric relative, Western monkshood (''Aconitum columbianum''). USDA-USFS, Pacific Northwest Research Station, Portland. |