[1] RDF Schema 1.1 ( (2014-02-27 21:42:23 +09:00 版)) <https://dvcs.w3.org/hg/rdf/raw-file/default/rdf-schema/index.html#h3_ch_label>
[2] Web Annotation Vocabulary (2017-02-24 02:14:26 +09:00) <https://w3c.github.io/web-annotation/vocab/wd/#rdfs-label>