TY  - BOOK
AU  - Beckmann Martin J
AU  -  Puu Tonu
TI  - Spatial structures
U1  - X:89K:(B), N0 
PY  - 1990///
CY  - Berlin
PB  - Springer-Verlag          
KW  - Regional Economics
N1  - Bib: p 131-33
ER  -