TY  - RPRT
TI  - Spatial aggregation in gravity models: 4. Generalisations and large-scale applications.
AU  - M Batty
AU  - P K Sikdar
PY  - 1982
DO  - 10.1068/a140795
UR  - https://pubmed.ncbi.nlm.nih.gov/12265202/
ID  - 12265202
ER  -