Which location has a method of decision and Nikos Tsoukalas for an opponent?
CREATE TABLE "kickboxing_record" (
  "result" text,
  "record" text,
  "opponent" text,
  "method" text,
  "location" text
);
SELECT "location" FROM "kickboxing_record" WHERE "method"='decision' AND "opponent"='nikos tsoukalas';