Morgan, R. P. C. (1998). Soil erosion and conservation. (2nd ed.). Longman.
Chicago-viite (17. p.)Morgan, R.P.C(Royston Philip Charles). Soil Erosion and Conservation. 2nd ed. Essex: Longman, 1998.
MLA-viite (9. p.)Morgan, R.P.C(Royston Philip Charles). Soil Erosion and Conservation. 2nd ed. Longman, 1998.
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