Question:
Which employer did Mary Douglas work for in Oct, 1984?

Context:
 Mary Douglas works for Russell Sage Foundation from Jan, 1977 to Jan, 1977. 
 Mary Douglas works for Columbia University from Jan, 1979 to Jan, 1980. 
 Mary Douglas works for University College London from Jan, 1951 to Jan, 1978. 
 Mary Douglas works for University of Illinois system from Jan, 1969 to Jan, 1969. 
 Mary Douglas works for University of Paris from Jan, 1967 to Jan, 1967. 
 Mary Douglas works for Northwestern University from Jan, 1981 to Jan, 1985. 
 Mary Douglas works for Yale University from Jan, 1980 to Jan, 1981. 
 Mary Douglas works for New York University from Jan, 1978 to Jan, 1979. 
 Mary Douglas works for University of Chicago from Jan, 1969 to Jan, 1969.

Answer:
Northwestern University