List out the nation of players who played for the 1997-1998 season .
players refers to PlayerName; 1997-1998 season refers to SEASON = '1997-1998';
SELECT DISTINCT T2.nation FROM SeasonStatus AS T1 INNER JOIN PlayerInfo AS T2 ON T1.ELITEID = T2.ELITEID WHERE T1.SEASON = '1997-1998'