52091
The later work , in the 3rd century BC , of Archimedes and Apollonius studied more systematically problems on conic sections , and also involved the use of coordinates .
 Archimedes, Apollonius
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Archimedes, Apollonius