Knudson, Douglas M. <br/><br/>
Outdoor recreation 
Douglas M. Knudson. 
 - New York  Macmillan  1980 
 - 655 pages:   illustration;    26cm. 
<br/><br/>Includes bibliographical references and index 
<br/><br/><label>ISBN: </label>0023653507 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Outdoor recreation--United States--Management<br/>Natural resources--Management--United States