Every book cited on this web has a template of its own, {{barrett_book12a}}-style, written in the format described under Referencing. This category gathers them.

They land here through a <noinclude>[[Category:Books]]</noinclude> at the foot of each template. The noinclude is the whole trick: it keeps the category on the template page itself, so a page that cites a book is not dragged into this category along with it.

bib2wiki writes that line for every book, chapter and thesis it renders, so a template made from Books.bib — by hand with bib2wiki <key>, or straight from an ISBN with isbn2bib -a — arrives already catalogued.

The same books rendered in full, rather than listed as template names, are under The books.