@article{Zipf1946,
author = {Zipf, G.K.},
title= {The P1P2/D hypothesis: On the intercity movement of persons},
year = {1946},
doi = {10.2307/2087063},
URL = {https://doi.org/doi:10.2307/2087063},
volume = {11},
number = {6},
pages = {677‒686},
}