title: Collaborations span 1,553 kilometres.
authors.forename: Robert J W
authors.initials: RJ
authors.lastname: Tijssen
authors.forename: Ludo
authors.initials: L
authors.lastname: Waltman
authors.forename: Nees Jan
authors.initials: NJ
authors.lastname: van Eck
mesh_terms: D003142:Communication; D003299:Cooperative Behavior; D006801:Humans; D007391:International Cooperation; D012586:Science / Q000706:statistics & numerical data* / Q000639:trends