- Ronco, F. 1961. Planting in beetle-killed spruce stands. United States Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, Research Note RM-60. 6 p.
- Ronco, F. 1967. Lessons from artificial regeneration studies in a cutover beetle-killed spruce stand in western Colorado. United States Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, Research Note RM-90. 8 p.