References
- Oregon and the Outdoors
Western Wood Products Association
- Douglas Fir
Softwood Export Council
- Douglas Fir
Weyerhauser
- Douglas Fir
Council of Forest Industries Canada
- Douglas Fir
From the West Coast of U.S.A. and Canada
The Australian Timber Importers Federation
Coast Forest and Lumber Association
- Forests Facts
Council Of Forest Industries
- The Douglas Fir of the Southern Rocky Mountains
Stuart Wier
