1. Extraction and characterization of humus with reference to clay-associated humus;Anderson;Can. J. Soil Sci.,1974
2. A comparison of humic fractions of Chernozemic and Luvisolic soils by elemental analyses, UV and ESR spectroscopy;Anderson;Can. J. Soil Sci.,1974
3. Total nitrogen;Bremner,1965
4. The System of Soil Classification for Canada;Canada Soil Survey Committee,1974
5. The plant factor in soil formation;Crocker,1960