Little Einsteins - 2005 Knock on Wood 1-24 is rated/received certificates of:
Knock Out - 2010 is rated/received certificates of: Singapore:PG
Postman's Knock - 1962 is rated/received certificates of: UK:U
Knock - 2011 II V is rated/received certificates of: USA:M/PG
Screenplay - 1986 Journey to Knock 6-12 is rated/received certificates of: Australia:M
Hannah Montana - 2006 Knock Knock Knockin' on Jackson's Head 3-11 is rated/received certificates of: Australia:G
Law and Order - 1990 Knock Off 19-5 is rated/received certificates of: USA:TV-14
Don't Knock the Rock - 1956 is rated/received certificates of: Finland:S Sweden:Btl USA:TV-G West Germany:12 (nf)
Knock on Any Door - 1949 is rated/received certificates of: Finland:K-16 Sweden:15 West Germany:12 (f)
Knock on Wood - 1954 is rated/received certificates of: Finland:K-16 Sweden:15 USA:Approved (PCA #16693) West Germany:6 (nf)
Don't Bother to Knock - 1961 is rated/received certificates of: Finland:K-16 UK:A (original rating) UK:PG (video rating) (1990)
The Good Wife - 2009 Waiting for the Knock 4-5 is rated/received certificates of: Netherlands:12 USA:TV-14
Bad Manners Don't Knock the Bald Heads - 2005 V is rated/received certificates of: UK:E (video premiere)