Servicio de parques nacionales areas silvestres de Nicaragua (primer borrador)
1983
Dilger F., R. |
Protected areas
Areas prioritarias para la conservación en la Región Oriental del Paraguay
1990
Acevedo, Celeste |
A selection of unpublished WWF project reports
1990
Stone, R. David |
Friends of the National Parks : a report on friends group throughout the National Park System
1993
Machlis, Gary E. |
Medlin, Nancy C. |
For the conservation of the Earth
1988
Martin, Vance |
