@article{odlyzko_2015, 
  title={The Forgotten Discovery of Gravity Models and the Inefficiency of Early Railway Networks}, 
  DOI={10.4000/oeconomia.1684}, 
  number={5-2}, 
  publisher={OpenEdition}, 
  author={Odlyzko}, 
  year={2015}, 
  month={Jun}
  }