Who played in the semi finals matches at the Buick WCT finals?
CREATE TABLE "wct_1985" (
  "date_final" text,
  "tournament" text,
  "commercial_name" text,
  "category" text,
  "prize_money_surface" text,
  "final_match" text,
  "semifinal_matches" text
);
SELECT "semifinal_matches" FROM "wct_1985" WHERE "commercial_name"='Buick WCT Finals';