100920
Four standard gauge 0 - 6 - 0 tank locomotives were built by two different manufacturers , two by Robert Stephenson and Company , and two by the Vulcan Foundry .
 Robert Stephenson and Company, Vulcan Foundry
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:
 Robert Stephenson and Company, Vulcan Foundry