87438
Its sedative properties were observed by Rudolf Buchheim in 1861 , but only described in detail and published by Oscar Liebreich in 1869 ; subsequently , because of its easy synthesis , its use became widespread .
 person: Rudolf Buchheim; person: Oscar Liebreich
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
 Entities: Rudolf Buchheim, Oscar Liebreich 
Answer:
 person: Rudolf Buchheim; person: Oscar Liebreich