Fritz, D. A., & Fritz, R. J. (2013). MARC21 for everyone: A practical guide. Indiana Publishing House.
Lua i Stíl Chicago (17ú heag.)Fritz, Deborah A., agus Richard J. Fritz. MARC21 for Everyone: A Practical Guide. India: Indiana Publishing House, 2013.
Lua MLA (9ú heag.)Fritz, Deborah A., agus Richard J. Fritz. MARC21 for Everyone: A Practical Guide. Indiana Publishing House, 2013.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.