Hudson, Norman. creator text Ames Iowa State University Press 1995 Fully rev. and updated, 3rd ed. monographic 391 p. : ill., maps ; 22 cm. Norman Hudson. Includes bibliographical references and index. Soil conservation Soil erosion S623 .H78 1995 631.4/5 0713473533 95191346 UOEL 000 20150615144006.0 3516496