Knock on Wood - 1954 is rated/received certificates of:
Finland:K-16
Sweden:15
USA:Approved (PCA #16693)
West Germany:6 (nf)
Little Einsteins - 2005 Knock on Wood 1-24 is rated/received certificates of: Australia:G
Love in a Wood - 1915 is rated/received certificates of: UK:U
Dead Wood - 2007 is rated/received certificates of: UK:15 USA:R
A Kiss for Jed Wood - 2011 is rated/received certificates of: Ireland:15A
Victoria Wood - 1989 is rated/received certificates of: UK:PG (2007 DVD release)
The Mystery of Natalie Wood - 2004 TV is rated/received certificates of: Australia:PG
Victorious - 2010 The Wood 1-17 is rated/received certificates of: Netherlands:AL
Knock on wood means you are hoping that it happens.
Hidden Treaure of Wompkee Wood - 2009 is rated/received certificates of: Portugal:M/4
Under Milk Wood - 1972 is rated/received certificates of: Iceland:L UK:15 UK:AA USA:PG
Smurfs - 1981 Smurf on Wood 4-11 is rated/received certificates of: Australia:G
Knock on wood means you are hoping that it happens.