1. Antipov-Karataev, I. N., And V. V. Kellerman: Die Bodenaggregate und ihre Kolloid-chemische Analyse. Z. Pflanzenernahr., Dung., Bodenkde. 98 (143), 193–204 (1962).
2. Baver, L. D.: Soil physics. New York: Wiley, and London: Chapman & Hall. 1948.
3. Blanck, E.: Handbuch der Bodenlehre, Vol. I-X. Berlin: Springer. 1928- -1932.
4. Boekel, P.: Some remarks on the influence of soil structure on plant growth. Intern. Symposium on Soil Structure (1958); Mededel. Landbouwhoge- school, Gent, 24, 52–57 (1959).
5. Boekel, P.: The amelioration of the structure of clay soils by liming. Intern. Symposium on Soil Structure (1958); Mededel. Landbouwhogeschool, Gent, 24, 122–127 (1959).