Declaration

<!ENTITY % book-meta-model
                        "(book-id+, book-title-group,
                         volume?, volume-id*, edition?, series*,
                         (contrib-group | aff | author-notes)*,
                         publisher*, isbn*,
                         pub-date*, history?, copyright-statement?,
                         copyright-year?,  permissions?,
                         self-uri*, alternate-form*,
                         abstract*, trans-abstract*, kwd-group*,
                         counts?,
                         (%address-link.class; | %custom-meta.class; |
                          %front-back.class;)* )"                    >