CREATE TABLE table_11803648_20 (nationality VARCHAR2, club_team VARCHAR2)

What is the Nationality when the club team is Peterborough Petes (OHL)?
SELECT nationality FROM table_11803648_20 WHERE club_team = "Peterborough Petes (OHL)"
SELECT "nationality" FROM "table_11803648_20" WHERE "Peterborough Petes (OHL)" = "club_team"