1. Aguilar, R.: 1981,Soil-Landscape Relationships of the Tionesta Research Natural Area, Pennsylvania, M. S. Thesis, Cornell University.
2. Andersen, S. B.: 1988,Long-Term Changes (1930-32 to 1984) in the Acid-Base Status of Forest Soils in the Adirondacks of New York, Ph. D. Thesis, University of Pennsylvania.
3. Billett, M. F., FitzPatrick, E. A. and Cresser, M. S.: 1993,Applied Geochem. Suppl. Issue No. 2, 179.
4. Brown, J. R. and Warncke, D.: 1988, ‘Recommended cation tests and measures of cation exchange capacity’, in W. C. Dahnke (ed.),Recommended Chemical Soil Test Procedures for the North Central Region. North Dakota Ag. Exp. Stn. North Central, Reg. Pub. No. 221, 37 p.
5. Craul, P. J.: 1964,An Analysis of Site Index Variation and Certain Soil Characteristics of Dekalb Very Stony Sandy Loam, Ph. D. Thesis, The Pennsylvania State University, 128 pp.