“ Author research For numbers of authors and writers that Wikisource collects their work, we have found that often that tertiary citable sources are less available. So we encourage that identifying sources — be they primary, secondary or tertiary — are noted on author talk pages as finding aids for future researchers, or to enable data completion at Wikidata.
Authors with no known public domain or free texts Most modern authors have no works in the public domain due to the long terms of copyright. ”