McLean, Wallace J. (1 January 2004). "Happy Public Domain Day!". American University. Archived from the original on 3 June 2017. Retrieved 9 March 2016.
Stefan Michel, Digitisation of art in the public domain–museum urges Wikimedia to take down reproductions of out-of-protection artworks, Journal of Intellectual Property Law & Practice, Volume 14, Issue 6, June 2019, Pages 427–429, doi:10.1093/jiplp/jpz042
Ignasi Labastida, Thomas Margoni; Licensing FAIR Data for Reuse. Data Intelligence 2020; 2 (1-2): 199–207. doi: https://doi.org/10.1162/dint_a_00042, p.203
Boyle, J. (2008). "A Creative Commons". The Public Domain: Enclosing the Commons of the Mind. Yale University Press. pp. 179–204. ISBN978-0-300-14275-4. JSTORj.ctt1npvzg.12.
skein_NIST_CD_121508.zipArchived 10 June 2016 at the Wayback Machine on skein-hash.info, skein.c "Implementation of the Skein hash function. Source code author: Doug Whiting, 2008. This algorithm and source code is released to the public domain."
skein_NIST_CD_121508.zipArchived 10 June 2016 at the Wayback Machine on skein-hash.info, skein.c "Implementation of the Skein hash function. Source code author: Doug Whiting, 2008. This algorithm and source code is released to the public domain."
McLean, Wallace J. (1 January 2004). "Happy Public Domain Day!". American University. Archived from the original on 3 June 2017. Retrieved 9 March 2016.