Question: who is younger Joakim Nyström or Kimberly Po ?
Related documents: [0]  [DOC] Kimberly Po-Messerli (born October 20, 1971) is a former professional tennis player from the United States. [END] 
[1]  [DOC] Joakim "Jocke" Nyström (born 20 February 1963) is a former top ten ranked tennis player from Sweden who won 13 singles titles during his professional career. The right-hander reached his highest singles ranking on the ATP Tour on 31 March 1986, when he was ranked World No. 7 and was also ranked as high as World No. 4 in doubles that same year. [END] 
Answer: 
Kimberly Po-Messerli
Kimberly Po-Messerli