Geographic Constraints on Social Network Groups

• Jukka-Pekka Onnela ,

  Contributed equally to this work with: Jukka-Pekka Onnela, Samuel Arbesman

  * E-mail: onnela@med.harvard.edu

  Affiliation Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts, United States of America

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• Samuel Arbesman ,

  Contributed equally to this work with: Jukka-Pekka Onnela, Samuel Arbesman

  Affiliation Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts, United States of America

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• Marta C. González,

  Affiliation Department of Civil and Environmental Engineering and Engineering Systems, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America

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• Albert-László Barabási,

  Affiliations Department of Physics, Biology and Computer Science, Center for Complex Network Research, Northeastern University, Boston, Massachusetts, United States of America, Center for Cancer Systems Biology, Dana Farber Cancer Institute, Boston, Massachusetts, United States of America, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America

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• Nicholas A. Christakis

  Affiliations Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts, United States of America, Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America, Department of Sociology, Harvard Faculty of Arts and Sciences, Cambridge, Massachusetts, United States of America

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