Knocking
- Año: 2006
- País: United States of America
- Género: Documental
- Estudio: Corporation for Public Broadcasting, Open Door Productions, ITVS
- Palabra clave: holocaust (shoah), bible, blood transfusion, civil liberties, jehovah's witness, the watchtower
- Director: Joel Engardio, Tom Shepard
- Emitir: Jason Edling, Seth Thomas, Joseph Kempler, Lillian Gobitas-Klose