TY  - BOOK
AU  - Ullman Edward L
TI  - Geography as spatial interaction. edited by Ronald
SN  - 0295957115
U1  - U, M0 
PY  - 1980///
CY  - Seattle
PB  - University of Washington Press       
KW  - Geography-Urban
N1  - Bibliography p.223-25; Appendix p.217-22
ER  -