[4] Christy C D. Computers and Electronics in Agriculture, 2008, 61: 10.
[5] Morgan C L S, Waiser T H, Brown D J, et al. Geoderma, 2009, 151: 249.
[6] Wang B W, Zhou W J, Ma S, et al. Agricultural Sci. & Tech., 2012, 13(4): 838.
[7] Viscarra Rossel R A, Chen C. Remote Sensing of Environment, 2011, 115: 1443.
[8] Viscarra Rossel R A, Behrens T. Geoderma, 2010, 158: 46.
[9] Burgess T M, Webster R. Journal of Soil Science, 1980, 31(2): 333.
[10] Sherman D M, Waite T D. American Mineralogist, 1985, 70: 1262.
[11] Hunt G R, Salisbury J W. Modern Geology, 1970, 1(4): 283.
[12] Clark R N, King T V V, Klejwa M, et al. Journal of Geophysical Research, 1990, 95: 12653.
[13] Clark R N. Spectroscopy of Rocks and Minerals, and Principles of Spectroscopy. In: Rencz, A N. (Ed. ), Remote Sensing for the Earth Sciences: Manual of Remote Sensing. John Wiley & Sons, New York, 1999, 3.