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In 2003 , Zaliznyak published the first comprehensive study of the Novgorod Codex , the earliest extant East Slavic book , which had been sensationally discovered three years earlier .
 Zaliznyak, Novgorod
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Zaliznyak, Novgorod