Nationalism 54,962 Natural history 42,407 National security 41,055 Nutrition 30,097 Nobility 28,138 Navigation 27,527 Natural resources 25,036 Nursing 22,818 Names, Geographical 21,866 Newspapers 20,412 Noncitizens 19,361 National parks and reserves 17,441 Navies 17,193 Nature 17,096 National socialism 16,761 Nuclear energy 14,160 Nuclear power plants 14,144 Nervous system 13,937 Neoplasms 13,765 Names, Personal 12,607 Nuclear weapons 12,000 Natural gas 11,669 Names 11,427 Numismatics 9,956 Natural disasters 9,753 Naval operations 9,603 Nonprofit organizations 9,330 Nurses 9,140 Napoleonic Wars, 1800-1815 8,638 Narration (Rhetoric) 8,494 Nanotechnology 8,399 Non-governmental organizations 7,955 Nature conservation 7,703 Nautical charts 7,701 NATURE 7,674 Neurology 7,253 Neurosciences 7,228 Nuclear physics 7,168 Numerical analysis 7,139 Nuclear reactors 7,068 New business enterprises 6,838 Nationalists 6,720 Natural law 6,401 Nuclear nonproliferation 6,286 Nanostructured materials 6,117 Nervous System Diseases 5,734 Neutrality 5,559 Number theory 5,474 National income 5,470 Nutritional Physiological Phenomena 5,423 Neolithic period 5,173 Neoliberalism 4,758 Nuclear disarmament 4,652 Noirs américains 4,648 Neuropsychology 4,633 Nature in literature 4,580 Nuclear industry 4,532 National characteristics, American 4,505 Neural networks (Computer science) 4,499 Nuclear arms control 4,446 Natural theology 4,434 Nuclear warfare 4,394 Negotiable instruments 4,383 Naturalists 4,378 National Government Expenditures and Related Policies: General 4,344 Numerical solutions 4,281 Novelists, English 4,275 Nationalisme 4,274 Navajo Indians 4,145 Noise 4,122 National accounts 4,114 Naval art and science 4,107 Name 4,075 Negotiation 4,052 Notaries 3,963 Nuclear facilities 3,928 Nuns 3,870 Neo-Confucianism 3,865 Naval history 3,770 Neighborhoods 3,741 Novelists, American 3,726 Nazi concentration camps 3,644 Navy-yards and naval stations 3,540 Nervous System 3,540 National songs 3,511 Nazis 3,473 New products 3,459 Nonfiction 3,436 National liberation movements 3,402 National characteristics, Japanese 3,393 Naturalization 3,353 Nutritional aspects 3,351 Neurophysiology 3,344 Nominations for office 3,327 National 3,320 Nursing homes 3,261 National health services 3,224 Nutrition policy 3,196 Newspaper publishing 3,184 Nomads 3,146