World Health Organization 80 Series 16 Guidelines 9 Risk assessment 9 Delivery of health care 6 Developing countries 6 Food and Agriculture Organization of the United Nations 5 Cost of illness 4 Health policy 4 Manuals 4 Research 4 World health 4 Biological products standards 3 Child 3 Communicable disease control 3 Disease vectors 3 Drug resistance 3 Environmental health 3 Malaria economics 3 Malaria prevention and control 3 Practice guideline 3 Quality control 3 Reference standards 3 Vaccines standards 3 Water supply standards 3 World Health Organization history 3 Air pollution, indoor 2 Alcohol drinking adverse effects 2 Asia Pacific Observatory on Health Systems and policies 2 Centers for Disease Control and Prevention (U.S.) 2