user: Question: Who wrote the episode directed by Jos Humphrey that had an original Canadian air date that was Unknown and a United States original air date of August 27, 2011?
Columns: ['Series #', 'Production Code', 'Title', 'Directed by', 'Written by', 'United States Original Airdate', 'Canada Original Airdate']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 101.0, '"The Yipper Caper"', 'Richard Weston', 'Paul Germain & Joe Ansolabehere', 'October 10, 2010', 'Unknown']
SQL:

assistant: SELECT "Written by" FROM "Table" WHERE "Directed by" = 'Jos Humphrey' AND "Canada Original Airdate" = 'Unknown' AND "United States Original Airdate" = 'August 27, 2011';