Kern, M. Kathleen
Virtual reference best practices: tailoring services to your library
American Management Association, 2009
 eBooks
Kovacs, Diane K.
The virtual reference handbook : interview and information delivery techniques for the chat and e-mail environments
Facet Publishing, 2007
 Buku Referensi
Personnel issues in reference services
edited by Bill Katz and Ruth A. Fraley
Haworth Press, 1986
 Buku Referensi
Hani Kusumaningsih
Evaluasi layanan referensi e-mail Perpustakaan United Nations Information Centre Jakarta = Evaluation of e-mail reference at United Nations Information Centre Library Jakarta
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 2016
 UI - Skripsi Membership
Librarians on the internet : impact on reference services
editor by Robin Kinder
The Haworth Press, 1994
 Buku Teks SO