Public Domain
Any work in the public domain, which means not under copyright protection, would be eligible for digitization without permission. Nevertheless, it should be properly attributed to the author. These public domain works may be available to anyone who visits the library´s website.
Which works are in the public domain now? Lopatin (2006) described public domain items as works “published before 1923 and US government publications… [which] can legally be digitized and put on the web as long as there are no privacy or publicity concerns” (p. 278).
Also, creative commons licenses can allow for free copying and distribution. The Creative Commons website offers more information.