TY  - JOUR
A1  - Zipf, G.K.
T1  - The P1P2/D hypothesis: On the inter-city movement of persons
Y1  - 1946
DO  - 10.2307/2087063
JF  - Amerian Sociological Review
VL  - 11
IS  - 6
SP  - 677
EP  - -686

ER  -