1. Binnedge, Robert W., The Pacific Northwest Lumber Industry and its Development. Yale University-School of Forestry 1923. Lumber Industry Series IV.
2. Ebner, Adalbert, Bersuchswesen und forstltche Forschung in den Bereinigten Staaten von Amerika. Forstw. Centralbl. 1936, S. 361.
3. The Timberman, Pacific Logging Congress Celebrates Silver Jubilee, November 1934, S. 25.
4. Drake, Geo L., Selective Logging. The Timberman, Nov. 1935, S. 18.
5. Brown, R. M., Viewpoint of the Forester. The Timberman, Nov. 1935, S. 18.