Sources are preferred in this order: primary peer-reviewed studies and original historical records; systematic reviews, meta-analyses, and scholarly handbooks; university-press books and standard textbooks; reputable science organisations; high-quality journalism for context; and popular books, blogs, and archives as leads only, unless clearly labelled as such.
Every bibliography record in the Library is opened and checked
by an editor before it is cited anywhere on the site, and carries a
reviewStatus field recording that check. Quotations are verified
character-for-character against the source, and controversial claims cite
both the strongest supporting work and the strongest relevant critique.