Rationalization of ploughing operations for drainage 

 - Geneva:  United Nations Publication,  1965 
 - 27p.:  ill., graphs, maps;  23 cm. 
 - Joint Committee on Forest Working Techniques and Training of Forest Workers    .
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>Dewey Class. No.: </label>634.927  / ECE