Abstract

References
1.
Rector
NA
Beck
AT
. Cognitive behavioral therapy for schizophrenia: An empirical review . J Nerv Ment Dis . 2001 ;189 :278 –287 .
2.
Reveiz
L
Cardona
AF
Ospina
EG
An e-mail survey identified unpublished studies for systematic reviews . J Clin Epidemiol . 2006 ;59 :755 –758 .
3.
van Driel
ML
De Sutter
A
De Maeseneer
J
Searching for unpublished trials in Cochrane reviews may not be worth the effort . J Clin Epidemiol . 2009 ;62 :838 –844 .
