1- Barker, E.A., Procopiou, J. and Janoudi, A., 2000. The leaf and fruit cuticles of selected drought tolerant plants. In: M.J. Bukovac (ed.) International Symposium on Growth and Development of Fruit Crops. East Lansing, Michigan, USA, 19-21 June, 1997. Acta Horticulturae, 527: 85-93.
2- Boone, F.R., Bouma, J. and De Smet, L.A.H., 1978. A case study on the effect of soil compaction on potato growth in a loam sand soil. Netherlands Journal of Agricultural Science, 26: 405-420.
3- Boone, F. R., Kroesbergen, B. and Boers, A., 1984. Soil conditions and growth of spring barley on a tilled and untilled marine loam soil. A joint study of the Westmaas Research Group on New Tillage Systems. Center for Agricultural Publishing and Documentation, The Netherlands. Agricultural Research Report No. 925: 124-166.
4- Carter, L.M., Stockton, J.R., Tavernetti, J.R. and Colwich, R.F., 1965. Precision tillage for cotton production. Transaction of ASAE, 8(2): 177-179.
5- Clark, L.J., Whalley, W.R. and Barraclough, P.B., 2003. How do roots penetrate strong soil. Plant and Soil, 255: 93-104.
6- Dichio, B., Nuzzo, V., Xiloyannis, C., Celano, G. and Anelopoulos, K., 1997. Drought stress-induced variation of pressure-volume relationships in Olea europaea L. cv. “Coratina”. In: II International Symposium on Irrigation of Horticultural Crops. ISHS Acta Horticulturae, 449: 401-410.
7- Dichio, B., Xiloyannis, C., Anelopoulos, K., Nuzzo,V., Bufo, S.A. and Celano, G., 2003. Drought induced variations of water relations parameters in olea europaea. Plant and Soil, 257: 381-389.
8- Fernandez, J.E. and Moreno, F,. 1999. Water use by the olive tree. In: M.B. Kirkham (ed.) Water use in crop production. Haworth Press, Inc.: 101-162.
9- Fernandez, J.E., Moreno, F., Giron, I.F. and Blazquez, O.M., 1997. Control of water consumption by the olive tree. In: II International Symposium on Irrigation of Horticultural Crops. ISHS Acta Horticulturae, 449: 83-90.
10- Kirkegaard, J.A., 1990. The effects of compaction on the growth of Pigeon Pea on clay soils. University of Queensland. A thesis submitted for the degree of Doctor of Philosophy, 289 p.
11- Lowry, F.E., Taylor, H.M. and Huck, M.G., 1970. Growth rate and yield of cotton as influenced by depth and bulk density of soil. Soil Science Society of America Proceedings, 34: 306-309.
12- Phillips, R. E. and Kirkham, D., 1962. Soil compaction in the field and corn growth. Agronomy Journal, 54: 29-34.49.
13- Rogers, H.T. and Thurlow, D.L., 1973. Soybeans restricted by soil compaction. Highlights of agriculture research. AuburnUniversity Agricultural Experiment Station, Auburn, AL 20 (10).
14- Russell, R. S., 1977. Plant root systems: Their function and interaction with the soil. McGraw-Hill (UK), Maidenhead, Berkshire, England: 298 p.
15- Sardabi, H., 1997. An investigation of the relationship between penetration resistance, soil physical properties and the growth of selected tree species. A thesis submitted for the degree of Doctor of Philosophy. Department of Forestry. The AustralianNationalUniversity: 144 p.
16- Scott, T. W. and Erickson, A. E., 1964. Effect of aeration and mechanical impedance on the root development of alfalfa, sugar beets and tomatoes. Agronomy Journal, 56: 575-576.
17- Sheesley, R., Grimes, D.W. and McClellan, W. D., 1974. Influence of wheel traffic on yield and stand longevity of alfalfa. Californian Agriculture: 28: 6-8.
18- So, H.B., 1987. Soil physical factors limiting crop establishment. In: I. M., Wood, W. H., Hazard, and F. R., From, (eds.). Proceedings of Crop Establishment Workshop, AIAS Occasional Publication No. 34: 154-165.
19- Taylor, H. M. and Burnett, E., 1963. Influence of soil strength on root growth habits of plants. Soil Science, 98: 174-180.
20- Taylor, H.M., Locke, L.F. and Box, J.E., 1964. Pans in southern Great Plains soils: their effects on yield of cotton and grain sorghum. Agronomy Journal, 56: 542-545.
21- Taylor, H. M., Roberson, G. M., Parker, J. R. and Jessie, J., 1966. Soil strength-root penetration relations for medium to coarse textured soil materials. Soil Science, 102: 18-22.
22- Taylor, H. M., Huck, M.G. and Klepper, B., 1972. Root development in relation to soil physical conditions. In: D. Hillel (ed.) Optimising the soil physical environment toward greater crop yields. Academic Press, N. Y. and London: 57-77.
23- Tennant, D., 1975. A test of a modified line intersect method of estimated root length. Journal of Ecology, 63: 995-1001.
24- Trouse, A. C., 1966. Alteration of the infiltration permeability capacity of tropical soils by vehicular traffic. In: proceedings of First Pan-American Soil Conservation Congress. Sao Paulo, Brazil: 1103-1109.
25- Voorhees, W. B., 1977. Soil compaction: how it influences moisture, temperature, yield, root growth. Crops and Soils Magazine, 29: 7-10.
26- Voorhees, W. B., 1987. Assessment of soil susceptibility to compaction using soil and climatic data bases. Soil and Tillage Research 10: 29-38.
)