1. Allison F.E. 1973 Soil organic matter and its role in crop production. Elsevier Sci. Pub. Co. (Amsterdam) 637 p.
2. Avimelech Y., Polachek Y., Moses A. and Cohen E. 1971 The effects of manures on the fertility of compacted soils. Hasadeh 51, 316–318 (Hebrew).
3. Baver L.D. 1963 The effect of organic matter on soil structure. In Organic Matter and Soil Fertility Pontif. Acad. Sci. Scripta Varia 32, 383–413. North Holland Publ. Co Amsterdam.
4. Black C.A. 1968 Soil-plant Relationship, John Wiley and Sons Inc. N.Y. Second Edition, 792 p.
5. Broadbent F.E. 1968 Turnover of nitrogen in soil organic matter. In Organic Matter and Soil Fertility Pontif. Acad. Sci. Scripta Variam 32, 61–82. North Holland Publ. Co. Amsterdam.