8021
Similar to the local magnitude scale ( ) defined by Charles Francis Richter in 1935 , it uses a logarithmic scale ; small earthquakes have approximately the same magnitudes on both scales .
 person: Charles Francis Richter
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 person: Charles Francis Richter