CREATE TABLE table_61731 ("Result" TEXT, "Record" TEXT, "Opponent" TEXT, "Method" TEXT, "Location" TEXT)

Which location has a method of decision and Nikos Tsoukalas for an opponent?
SELECT "Location" FROM table_61731 WHERE "Method" = 'decision' AND "Opponent" = 'nikos tsoukalas'
SELECT "Location" FROM "table_61731" WHERE "Method" = 'decision' AND "Opponent" = 'nikos tsoukalas'