http://server.nanopubs.lod.labs.vu.nl/
http://130.60.24.146:7880/
https://openphacts.cs.man.ac.uk/nanopub/server/
http://server.np.dumontierlab.com/
http://server.np.scify.org/
https://server.nanopubs.knows.idlab.ugent.be/
https://server.np.trustyuri.net/
https://np.knowledgepixels.com/