TY  - BOOK
AU  - CASSELL, K.A.  AND UMMA H.
TI  - Reference and information services in the 21st century:an introduction
SN  - 9781555707408
AV  - Z 711  C37 2011 
PY  - 2011///
CY  - Neal-Schuman pub
PB  - New York 
ER  -