user: Question: Name who drected the episode written by George Tibbles
Columns: ['Episode #', 'Season #', 'Title', 'Directed by', 'Written by', 'Original airdate', 'Production code #']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'real']
Sample row: [96.0, 501.0, '"Adios, Johnny Bravo"', 'Jerry London', 'Joanna Lee', 'September14,1973', 98.0]
SQL:

assistant: SELECT "Directed by" FROM "Table" WHERE "Written by" = 'George Tibbles';