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16th - century technical writers such as Biringuccio , Ercker and Agricola described a variety of cementation brass making techniques and came closer to understanding the true nature of the process noting that copper became heavier as it changed to brass and that it became more golden as additional calamine was added .
 person: Biringuccio; person: Ercker; person: Agricola
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: Biringuccio, Ercker, Agricola 
Answer:
 person: Biringuccio; person: Ercker; person: Agricola