TY  - BOOK
AU  - Pirkle, E.C.; Yoho, W.H.
TI  - Natural regions of the United States / 
SN  - 084031258X  
AV  - GB 121  .P669 1975
U1  - HS 917.302  
PY  - 1975///.
CY  - Dubuque, Iowa : 
PB  - Kendall/Hunt Pub., 
ER  -