Table schema:
CREATE TABLE table_name_73 (station VARCHAR, services VARCHAR, zone_2008 VARCHAR, zone_2007 VARCHAR)

Question: Which Station has a Zone 2008 of 8, and a Zone 2007 of outside zones, and Services of london overground?
SQL: SELECT station FROM table_name_73 WHERE zone_2008 = "8" AND zone_2007 = "outside zones" AND services = "london overground"