The New America's Wonderlands / Our National Parks 
/ by: National Geographic Society 
 - Washington DC  National Geographic Society  1980 
 - 464 p.  ill. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology
<br/><br/><label>Subjects--Index Terms: </label>ეკოლოგია 
<br/><br/><label>Universal Decimal Class. No.: </label>577.4  / N-52