 Complete the following phrase:  Christina Liebetrau née Neumann; born 30 December 1953 is a former East German track and field athlete who competed in the 800 metres. She set a personal best of 1:58.81 minutes in 1976. Her sole international successes came in the 1977 season when she was a silver medallist at the 1977 IAAF World Cup and the winner at the 