CREATE TABLE table_78509 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

What was the away team that played at Princes Park?
SELECT "Away team" FROM table_78509 WHERE "Venue" = 'princes park'
SELECT "Away team" FROM "table_78509" WHERE "Venue" = 'princes park'