1. On the variability of amorphous materials in Andosols and their relationships to irreversible drying and P-retention;Andriesse;Geoderma,1976
2. Methods of chemical analyses for soils and waters;Begheijn,1980
3. Methods of soil analysis, 2;Black,1965
4. Methods for chemical analysis of soils;Blakemore;N.Z. Soil Bur. Sci. Rep.,1977
5. Proc. 1st Int. Soil Classific. Workshop,1978