Hays, Samuel P., <br/><br/>
Conservation and the gospel of efficiency :  the progressive conservation movement, 1890-1920 / 
Samuel P. Hays. 
 - 1 online resource (320 pages) 
<br/><br/> Originally published: Cambridge : Harvard University Press, 1959, in series: Harvard historical monographs, 40. 
<br/><br/>Includes bibliographical references (pages 277-282) and index. 
<br/><br/><label>ISBN: </label>9780822972037 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Conservation of natural resources--History.--United States<br/>Environmental policy--History.--United States
<br/><br/><label>Index Terms--Genre/Form: </label><br/>Electronic books.
<br/><br/><label>LC Class. No.: </label>S930  / .H38 1999 
<br/><br/><label>Dewey Class. No.: </label>333.7/2/0973