Question:
Which employer did Egor Babaev work for in Sep, 2002?

Context:
 Egor Babaev works for Uppsala University from Jan, 2001 to Jan, 2003. 
 Egor Babaev works for Royal Institute of Technology from Jan, 2006 to Dec, 2022. 
 Egor Babaev works for University of Massachusetts Amherst from Jan, 2007 to Jan, 2013. 
 Egor Babaev works for Cornell University from Jan, 2003 to Jan, 2006.

Answer:
Uppsala University