Cassell, K. A., & Hiremath, U. (2011). Reference and information services in the 21st century: An introduction (2nd ed. rev.). Neal-Schuman Publishers.
Παραπομπή σε μορφή Chicago (17η εκδ.)Cassell, Kay Ann, και Uma Hiremath. Reference and Information Services in the 21st Century: An Introduction. 2nd ed. rev. New York: Neal-Schuman Publishers, 2011.
Παραπομπή σε μορφή MLA (9th εκδ.)Cassell, Kay Ann, και Uma Hiremath. Reference and Information Services in the 21st Century: An Introduction. 2nd ed. rev. Neal-Schuman Publishers, 2011.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.