CREATE TABLE table_4998 ("Date" TEXT, "City" TEXT, "Opponent" TEXT, "Results\\u00b9" TEXT, "Type of game" TEXT)

Which opponent played a 1990 wcq type of game, where the results were 0:0?
SELECT "Opponent" FROM table_4998 WHERE "Type of game" = '1990 wcq' AND "Results\u00b9" = '0:0'
SELECT "Opponent" FROM "table_4998" WHERE "Results\u00b9" = '0:0' AND "Type of game" = '1990 wcq'