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The route of the next section to Oberhausen , Altenessen , Gelsenkirchen , Wanne , Herne and Dortmund to Hamm was chosen over a route close to the coal mines that were then located on the north bank of the Ruhr because it was cheaper to build as it largely avoided hills .
 Oberhausen, Gelsenkirchen, Herne, Dortmund, Hamm
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Oberhausen, Gelsenkirchen, Herne, Dortmund, Hamm