[1]- Xu, Z. X., Tang, L., Zhang, K., He, X. J., and Hou, W. L., 2014, Research on Survey Methods and Engineering Properties of Black Cotton Soil of Ethiopian Railway, Journal of Railway Engineering Society, 31, 2, 15-18.
[2]- Wagner, G. H. and Stevenson, F. J., 1965, Structural Arrangement of Functional Groups in Soil Humic Acid as Revealed by Infrared Analyses, Journal Soil Science Society of America Journal, 29, 2, 43-48.
[3]- Shao, W. M., Tan, L. R., Zhang, M. Y., and Hua, L. L., 1994, Experimental Study on Relationship between Mineral Composition and Swelling Characteristics of Expansive Soil, Journal of Rock and soil mechanics, 2, 11-19.
[4]- Gao, D. P., 2015, Study of Properties of Expansive Soil on the Ethiopia to Djibouti Railway (Dire Dawa-Dawanle Segment), Journal of Railway Investigation and Surveying, 3, 13-25.
[5]- Zhao, P., Xu, Z. X., Tang, L., and Zeng, D. L., 2014, Research on the Black Cotton Soil Swell-shrink Characteristics and the Depth of Black Cotton Soil Influenced by the Atmosphere in Ethiopia, Journal of Railway Engineering Society, 4, 46-50.
[6]- Mahjoory, R. A., 1996, Occurrence and mineralogy of a deposit of shampoo-clay in southern Iran, Journal of Applied Clay Science, 11, 1, 69-76.
[7]- Xu, Z. X., Zhang, K., and Tang, L., 2012, Comments on Engineering Geological Investigation of Ethiopian Railway, Journal of Railway Engineering Society, 29, 5, 26-29+39.
[8]- Wang, T., Fan, Q. B., Liu, X., and Wang, Y., 2014, Black Cotton Subgrade Treatment in East Africa, D. Chang’an University.
[9]- Chen, S. X., Li, F. B., Kong, L. W., 2006, Engineering behaviors of weak expansive soil and its treatment measures for roadbed filling, Journal of Rock and soil mechanics,27, 3, 353-359.
[10]- Zhang, D. F., Yang, J. L., Li, Y., and Shen, Z. P., 2015, Engineering properties of black cotton soil in East Africa and pile foundation disease treatment, Journal of Building Structure, 45, 1, 72-76.
[11]- Li, S. D., and Zhao, Z. X., 1993, Improvement of Engineering Properties of Expansive Soil by Using Mineral Slurry Composites, Journal of Chinese Journal of Geotechnical Engineering, 15, 5, 11-23.
[12]- Li, X. Y., and Zhang, X. H., Lime Improved Expansive Soil Filling Subgrade Construction Technology, Journal of Subgrade Engineering, 3, 47-49.
[13]-Folagbade, O., and George, M., 2010, Groundnut Shell Ash Stabilization of Black Cotton Soil, Electronic Journal of Geotechnical Engineering, 15, 415-428.
[14]- Santhi, K. K., and Sayida, M. K., 2009, Behavior of Black Cotton Soil Reinforced with Sisal Fibre, Journal of 10th National Conference on Technological Trends(NCTT09)6-7, 11, 88-93.
[15]- Shi, B., Li, S. L., and Tolkachev, M., 1995, Quantitative Study on SEM Images of Microstructure of Clay , Journal of Science in China (Series A), 6, 666-672.
[16]- Tovey, N. K., 1980, A digital computer technique for orientation analysis of micrographs of soil fabric, Journal of Microscopy, 120, 3, 303-315.
[17]- China Railway First Survey and Design Institute Group. Code for Rock and Soil Classification of Railway Engineering: TB 10077-2001, S. Beijing China Railway Press, 2001.
[18]-Ministry of Communications Highway Research Institute. Test Method of Soils for Highway Engineering: JTG E40-2007, S. Beijing China Communications Press. 2007
[19]- Zheng, J. L., 2013, Theory and Technology for Highway Expansive Soil Engineering, M. Beijing China Communications Press.