52387
According to William Thurston this normal form must take one of a small number of possibilities , each having a different kind of geometry , called Thurston model geometries .
 William Thurston, Thurston
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 William Thurston, Thurston