<a href="https://en.wikipedia.org/wiki/Walter_Christaller" class="extiw" title="w:Walter Christaller">Christaller's</a> first model of distribution of cities on space, according to the market principle.
<a href="//commons.wikimedia.org/w/index.php?title=User:Laotseuphilo&amp;action=edit&amp;redlink=1" class="new" title="User:Laotseuphilo (page does not exist)">Laotseuphilo</a>
2006-05-18
adapted from the book written by Christaller, "Die zentralen Orte in Süddeutschland" (1933)