Article with cool maps: http://www.atlasobscura.com/articles/here-are-the-real-boundaries-of-american-metropolises-decided-by-an-algorithm

Academic paper: http://journals.plos.org/plosone/article?id=info%3Adoi/10.1371/journal.pone.0166083

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Mara Kaminowitz, GISP
GIS Coordinator
.........................................................................
Baltimore Metropolitan Council
Offices @ McHenry Row
1500 Whetstone Way
Suite 300
Baltimore, MD  21230
410-732-0500 ext. 1030
mkaminowitz@baltometro.org
www.baltometro.org