Question:
Which employer did Gillian Hadfield work for in May, 1999?

Context:
 Gillian Hadfield works for University of Southern California from Jan, 2001 to Jan, 2018. 
 Gillian Hadfield works for New York University from Jan, 1999 to Jan, 2001. 
 Gillian Hadfield works for University of California, Berkeley from Jan, 1990 to Jan, 1994.

Answer:
Question:
Which employer did Gillian Hadfield work for in May, 1999?

Context:
 Gillian Hadfield works for University of Southern California from Jan, 2001 to Jan, 2018. 
 Gillian Hadfield works for New York University from Jan, 1999 to Jan, 2001. 
 Gillian Hadfield works for University of California, Berkeley from Jan, 1990 to Jan, 1994.

Answer:
user
New York University
assistant
Question:
Which employer did Gillian Hadfield work for in May, 1999?

Context:
 Gillian Hadfield works for University of Southern California from Jan, 2001 to Jan, 2018. 
 Gillian Hadfield works for New York University from Jan, 1999 to Jan, 2001. 
 Gillian Hadfield works for University of California, Berkeley from Jan, 1990 to Jan, 1994.

Answer:
user
University of California, Berkeley
University of Southern California
assistant
Question:
Which employer did Gillian Hadfield work for in May, 1999?

Context:
 Gillian Hadfield works for University of Southern California from Jan, 2001 to Jan, 2018. 
 Gillian Hadfield works for New York University from Jan, 1999 to Jan, 2001. 
 Gillian Hadfield works for University of California, Berkeley from Jan, 1990 to Jan, 1994.

Answer:
user
New York University
assistant