CREATE TABLE table_19098 ("Call sign" TEXT, "Analog channel" TEXT, "Digital channel" TEXT, "Virtual channel" TEXT, "Network" TEXT, "Station Ownership" TEXT)

What is channel 33.7's official call sign?
SELECT "Call sign" FROM table_19098 WHERE "Virtual channel" = '33.7'
SELECT "Call sign" FROM "table_19098" WHERE "Virtual channel" = '33.7'