1. The global burden of intestinal nematode infections – fifty years on;Chan;Parasitol. Today,1997
2. The evaluation of potential global morbidity attributable to intestinal nematode infections;Chan;Parasitology,1994
3. World Health Organization (2000) Communicable Diseases: Control of Schistosomiasis and Soil Transmitted Helminth Infections (report by the Secretariat), Executive Board, World Health Organization
4. The Global Burden of Disease,1996
5. Soil-transmitted helminthiases: nationwide survey in China;Xu;Bull. World Health Organ.,1995