2411
Croesus is credited with issuing the " Croeseid " , the first true gold coins with a standardised purity for general circulation , and the world 's first bimetallic monetary system circa 550 BCE .
 Croesus, Croeseid
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Croesus, Croeseid