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The blues researcher Mack McCormick began researching his family background in 1972 , but died in 2015 without ever publishing his findings .
 person: Mack McCormick
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: Mack McCormick 
Answer:
 person: Mack McCormick