TY  - BOOK
AU  - Jackson,Donald Dale
AU  - 
TI  - Underground worlds
PY  - 1982///
CY  - Alexandria, Va.
PB  - Time-Life Books
KW  - Caving
KW  - History
KW  - 19th century
KW  - 20th century
KW  - Caves
N1  - Includes index; Bibliography: p. 170-172
ER  -