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Other notable students included Doug Ring , a leg spinner who was a member of Bradman 's " Invincibles " , left arm orthodox spinner Jack Wilson and world record breaking Olympic distance runner Ron Clarke .
 Doug Ring, Bradman, Invincibles, Jack Wilson, Ron Clarke
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Doug Ring, Bradman, Invincibles, Jack Wilson, Ron Clarke