For the conservation of earth /
World Wilderness Congress(4th :1987 :Denver, Colo. and Estes Park, Colo.)
Martin, Vance.
Golden, Colo. : Fulcrum, Inc.,
c1988.
"Proceedings of the 4th World Wilderness Congress, held in Denver and Estes Park, Colorado"--Cover.
Includes bibliographies.
Nature conservation
Natural areas
Wilderness areas