Question:
Which employer did Wolfgang Rindler work for in Dec, 1968?

Context:
 Wolfgang Rindler works for University of Hamburg from Jan, 1962 to Jan, 1962. 
 Wolfgang Rindler works for University of Liverpool from Jan, 1947 to Jan, 1949. 
 Wolfgang Rindler works for University of London from Jan, 1949 to Jan, 1956. 
 Wolfgang Rindler works for University of Texas at Dallas from Jan, 1963 to Jan, 1963. 
 Wolfgang Rindler works for Sapienza University of Rome from Jan, 1968 to Jan, 1969. 
 Wolfgang Rindler works for Cornell University from Jan, 1956 to Jan, 1963. 
 Wolfgang Rindler works for King's College London from Jan, 1961 to Jan, 1962.

Answer:
Sapienza University of Rome