29035
In a study of citation patterns for database publication venues , TODS had the highest long-term impact , as measured by the frequency of citations to its papers , among any of the venues studied ; however , most of those citations were outside the two-year window in which the impact factor is conventionally measured .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None