1. Allen, R.H., Marquis, D.A., 1970. Effect of thinning on height and diameter growth of oak and yellow-poplar saplings. USDA For. Serv. Northeast. For. Exp. Sta. Res. Pap. NE-173, 11 pp.
2. Auchmoody, L.R., 1986. Fertilizing Appalachian hardwoods. In: Smith, H.C., Eye, M.L. (Ed.), Proceedings, Guidelines for Managing Immature Appalachian Hardwood Stands. West Virginia Univ. Office of Publications, Morgantown, WV, pp. 208–220.
3. Effects of urea and ammonium nitrate fertilizer on growth of a young thinned and unthinned Douglas-fir stand;Barclay;Can. J. For. Res.,1984
4. Beck, D.E., Della-Bianca, L., 1981. Yellow-poplar: characteristics and management. USDA For. Serv. Southeast. For. Exp. Sta. Agr. Hndbk. No. 583, 91 pp.
5. Hardwood growth can be increased by fertilization;Blackmon;South Lumberman,1974