275765
Derek Bell and Hans-Joachim Stuck makes an introduction on the foreword on the books , telling their experiences in the series .
 Derek Bell, Hans-Joachim Stuck
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Derek Bell, Hans-Joachim Stuck