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In the 1920 s , product improvement through the use of statistical process control was promoted by Dr. Walter A. Shewhart at Bell Labs , around the time that Waloddi Weibull was working on statistical models for fatigue .
 person: Walter A. Shewhart; organization: Bell Labs; person: Waloddi Weibull
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: Walter A. Shewhart; organization: Bell Labs; person: Waloddi Weibull