14155
Collecting data from Rumyantsev and university libraries , he hoped to write a study on Grand Duke Kęstutis .
 Rumyantsev, Kęstutis
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Rumyantsev, Kęstutis