1. Anderson HW Gordon AG 1994. The tolerant conifers: eastern hemlock and red spruce their ecology and management. Forest Research Information Paper - Ontario Forest Research Institute No. 113:48 pp.; 41 + 6 ref.
2. Burns RM Honkala BH 1990. Silvics of North America: 2. Hardwoods. Agriculture Handbook 654. Washington DC USA: U.S. Department of Agriculture Forest Service. Also available on the Internet (individual authors noted) at:
3. Burns RM Honkala BH eds. 1990. Silvics of North America. Volume 1. Conifers. Agriculture Handbook No. 654. Washington D.C. USA: USDA Forest Service. World Wide Web page at
4. Caldwell WF 2000. You have conifers in Texas? American Conifer Society Bulletin 17:31-33.
5. Ciesla WM 1998. Non-wood forest products from conifers. Rome Italy: Food and Agriculture Organization.