Question: What team won a two-leg Spanish football match played on 20 August and 23 August 1997, which one contestant won the 66th since its establishment, started on 31 August 1996 and finished on 23 June 1997?

Related documents: [0]  [DOC] The 1996–97 La Liga season, the 66th since its establishment, started on 31 August 1996 and finished on 23 June 1997. [END] 
[1]  [DOC] The 1997 Supercopa de España was a two-leg Spanish football match played on 20 August and 23 August 1997. The contestants were FC Barcelona, who were Spanish Cup winners in 1996–97, and Real Madrid, who won the 1996–97 Spanish League. Real Madrid won 5–3 on aggregate. [END]  
Answer: Real Madrid
Real Madrid