@techreport{9343936ea5144ce09b44c2e092929db6,
title = "Gravity and entropy models: the state of the art. Paper presented at the 'colloquium Vervoersplanologisch Speurwerk', The Hague, February 1978",
author = "P. Nijkamp",
year = "1977",
language = "English",
series = "Serie Research Memoranda",
publisher = "Faculty of Economics and Business Administration, Vrije Universiteit Amsterdam",
number = "1977-2",
type = "WorkingPaper",
institution = "Faculty of Economics and Business Administration, Vrije Universiteit Amsterdam",
}