97521
On 2 June , he cooperated with Collishaw , Ellis Vair Reid , and William Melville Alexander in forcing down a German observation plane .
 Collishaw, Ellis Vair Reid, William Melville Alexander
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Collishaw, Ellis Vair Reid, William Melville Alexander