2672
He resumed his studies only in 1902 when he wrote his PhD thesis in University of Greifswald .
 organization: PhD; organization: University of Greifswald
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: PhD, University of Greifswald 
Answer:
 organization: PhD; organization: University of Greifswald