CREATE TABLE table_name_85 (national_final_co_host VARCHAR(255), year_s_ VARCHAR(255), national_final_main_host VARCHAR(255), selection_show VARCHAR(255))
What is the name of the national final co host when David Jacobs was the National final main host, and the selection show was a song for europe in 1966?
    
SQL: SELECT national_final_co_host FROM table_name_85 WHERE national_final_main_host = "david jacobs" AND selection_show = "a song for europe" AND year_s_ = "1966"