Maududi, Sayyid Abul A`la
Islam today : with a brief life-sketch of the author
Dar Al-Qalam, 1968
 Buku Teks SO
Gilbert, Wilfred C.
The Legislative reference service
The Library of Congress, 1952
 Buku Teks
Yates, Rochelle
A librarian's guide to telephone reference service
Library Professional Publications, 1986
 Buku Teks SO
Park, Jae Dong
Silkroad sketch
Hangyorae Chulpan, 2007
 Buku Teks
Johnson, Julie K.
GILS: Government information locator service,a brief description Julie Johnson
1995
 Artikel Jurnal