9738
Caligula 's sister , Agrippina the Younger , wrote an autobiography that certainly included a detailed explanation of Caligula 's reign , but it too is lost .
 Caligula, Agrippina the Younger, Caligula
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Caligula, Agrippina the Younger, Caligula