Before you assume that you need to get permission, check to see if it is necessary. You may not need permission to use a work if
The copyright owner could be the original creator, the creator's heirs, or the publisher. Note that there may be several owners involved with one work. For example, in order to use recorded music, you may need to get permission from the composer, the performers, and the recording company.
To find the owner or owners,
Usually an internet search will be sufficient for locating an author or publisher, but sometimes the search for a copyright owner can become complex.
Sometimes it is impossible to identify, locate, or get a response from the copyright holder: you are dealing with an "orphan work". In this case, you may
In any case, carefully document your attempts to seek permission.