2009
They simply did n't know , but as I say , Admiral Koryerov has said he does believe it was a collision with a submarine , and they 're not sure now whether it was a foreign submarine or a Russian one ?
 Koryerov, Russian
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: date, organization, person, geographical social political, national religious political, facility, cardinal, location, work of art, law, event, product, ordinal, percent, time, quantity, money, language 
Text: {0} 
Answer:
 Koryerov, Russian