National parks and protected areas  : their role in environmental protection 
edited by R. Gerald Wright 
 - Cambridge  Blackwell  cop. 1996 
 - XVi, 470 p.  26 cm 
<br/><br/><label>ISBN: </label>0865424969 
<br/><br/><label>Subjects--Index Terms: </label>Reservas naturales Conservacion de la naturaleza Medio ambiente