• Accessions lists
• Anthologies
• Bibliographic journals
• Bibliographies
• Catalogues
• Directories
• Indexes
• Inventories
• Literature reviews
• Quotations
• Research registers

• Bookform materials
• Book reviews
• Nonbook materials

• A document containing data or information about "primary documents".

• Information and communication > Information sources

http://vocabularies.unesco.org/thesaurus/concept506