Brady, Nyle C. <br/><br/>
The nature and properties of soils / 
Nyle C. Brady ; Ray R. Weil. 
 - 13th ed. 
 - Upper Saddle River, N.J. :  Prentice Hall,  2002. 
 - xvi, 960 p. :  ill. (some col.), maps ;  29 cm.