Environmental interpretation :  A practical Guide for people with big ideas and small budgets / 
Ham, Sam H. 
 - USA :  North American Press,  c1992 
 - xxvi,456 pages :  ills.;  23cm.  Includes bibliographic references and indexes. 
<br/><br/><label>ISBN: </label>1 55591 902 2 
<br/><br/><label>Subjects--Personal Names: </label>--Natural areas - Interpretive programs.
<br/><br/><label>Dewey Class. No.: </label>333. 7 HAM