The books, articles, museum records, craft council publications, encyclopedia entries and official sites this atlas cites as evidence for what it asserts about a craft, hobby, tool, figure, institution, concept or milestone, each carrying an author or publisher, a year and a reliability tier where one can be established. A source entry is what a reader follows to check a claim rather than take the atlas's word for it, grouped here by the kind of publication it is: craft publications and suppliers, encyclopedia articles, museum features and records, official sites, organization pages and Wikipedia.