Halka Chronic

Roadside geology of Arizona

Halka Chronic, 1983 .

MOLLUSCAN FAUNA FROM THE PERMIAN KAIBAB FORMATION, WALNUT CANYON, ARIZONA

Halka Chronic, 1952 .

The high altitude observatory of the national center for atmospheric research, Boulder, Colo.

G. Newkirk, Halka Chronic, 1969 .

Roadside Geology of Utah

Halka Chronic, F. Williams, L. Chronic, 1980 .