216580
Part Two 1951-1956 , also consists of six chapters , all by Cynthia Koestler , followed by an Epilogue written by Harold Harris , an Appendix by Arthur Koestler , and an Index .
 Koestler, Harold Harris, Arthur Koestler
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Koestler, Harold Harris, Arthur Koestler