| <!ELEMENT bib (book* )> | |
| <!ELEMENT book (title, (author+ | editor+ ), publisher, price )> | |
| <!ATTLIST book year CDATA #REQUIRED > | |
| <!ELEMENT author (last, first )> | |
| <!ELEMENT editor (last, first, affiliation )> | |
| <!ELEMENT title (#PCDATA )> | |
| <!ELEMENT last (#PCDATA )> | |
| <!ELEMENT first (#PCDATA )> | |
| <!ELEMENT affiliation (#PCDATA )> | |
| <!ELEMENT publisher (#PCDATA )> | |
| <!ELEMENT price (#PCDATA )> |