Permission is not needed if the work in question is in the public domain. Works in the public domain are not protected by copyright. Below is a list of reasons why certain works might be in the public domain:
- Expiration of copyright: the copyright has expired.
- Before 1923
- Failure to renew copyright: the owner failed to follow copyright renewal rules.
- Anytime between 1923 and 1963 with copyright notice but not renewed
- Anytime between 1923 and 1977 with no copyright notice
- Anytime between 1978 and March 1, 1989 with no copyright notice and no registration, or to which author has given up rights
- Dedication: the owner deliberately places it in the public domain.
- A work of the United States government, or prepared by an officer or employee of the federal government as part of that person's official duties, is in the public domain.
Copyright Term and the Public Domain in the United States - Cornell University by Peter B. Hirtle
Digital Copyright Slider by the American Library Association & Michael Brewer to determine if it is in the public domain. http://librarycopyright.net/resources/digitalslider/