Lal R, Blum W H, Valentine C, & Stewart B A. (2014). Methods for assessment of soil degradation. CRC Press.
Dyfyniad Arddull ChicagoLal R, Blum W H, Valentine C, and Stewart B A. Methods for Assessment of Soil Degradation. New York: CRC Press, 2014.
Dyfyniad MLALal R, et al. Methods for Assessment of Soil Degradation. CRC Press, 2014.
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