1. Updated guidelines for evaluating public health surveillance systems;CDC, Guidelines Working Group;MMWR,2001
2. International Network of Paediatric Surveillance Units
First Progress Report, 1999–2002
(Version current at June 28, 2004).
3. World Health Organization
Effective surveillance system
(Version current at June 28, 2004).
4. Evaluation of a national surveillance unit;Gazarian;Arch Dis Child,1999