1. Estimated timber harvest by U.S. region and ownership, 1950-2002.
2. Agronomy Abstracts 1995 Proceedings, 87th Annual Meeting of ASA, CSSA, and SSSA, , St. Louis, MO. 29 Oct.-3 Nov. 1995 ASA, CSSA, and SSSA Madison, WI
3. Agronomy Abstracts 1996 Proceedings, 88th Annual Meeting of ASA, CSSA, and SSSA, Indianapolis, IN. 3-8 Nov. 1996 ASA, CSSA, SSSA Madison, WI
4. Allen , A.W. M.W. Vandever 2004 The Conservation Reserve Program-Planting for the future: Proceedings of a national conference, Fort Collins, CO. 6-9 June 2004