No apology for Wikipedia, either. For the vindication of Wikipedia as an academic source, Harvard University Library [a lead partner in the Digital Public Library of America (DPLA) Project] has expanded Wikipedia’s works on books to over 60,000 [Harvard Library Innovation Laboratory, ShelfLife Collaborative, Librarycloud Demo]:

... two-way integration with Wikipedia,... is ... an example of how DPLA can weave itself into the knowledge ecosystem of the Web. If an item has a Wikipedia page, we let you see all the other items categorized with it at Wikipedia.

    We're proud of this; it took considerable effort and ingenuity.
    …
    If the DPLA collection doesn't contain that work, we put the work's Wikipedia page on the shelf.

[see “How did you do the integration with Wikipedia?” on the FAQ page]