Optional
_publisherOptional
_titleName of the database or title of the book or journal
Optional
extensionAdditional content defined by implementations
Optional
idUnique id for inter-element referencing
Optional
identifierJournal identifiers include ISSN, ISO Abbreviation and NLMuniqueID; Book identifiers include ISBN
Optional
modifierExtensions that cannot be ignored even if unrecognized
Optional
publisherName of the publisher
Optional
publisherGeographic location of the publisher
Optional
titleName of the database or title of the book or journal
Optional
typeKind of container (e.g. Periodical, database, or book)
Geographic location of the publisher