Religious aspects 227,277 Research 199,993 Religion 154,803 Relations 124,032 Railroads 84,161 Roads 65,605 Race relations 58,416 Religious life 45,931 Russian literature 41,001 Regional planning 40,828 Russian language 35,309 Rural conditions 34,944 Real property 34,495 Rock music 33,781 Religious life and customs 32,836 Reference 32,056 Rhetoric 30,911 Refugees 30,847 Rural development 29,023 Rites and ceremonies 28,223 Rules and practice 24,860 Regimental histories 24,212 Rehabilitation 24,018 Reformation 21,972 Racism 20,844 Readers 20,327 RELIGION 20,257 Reading 19,848 Revolutionaries 18,778 Radio 16,706 Russian poetry 15,434 Roman law 14,946 Religions 14,779 Russian 14,674 Rabbis 14,634 Romanticism 14,346 Responsa 14,183 Rivers 13,919 Rare books 13,898 Representative government and representation 13,864 Renaissance 13,739 Religion and science 13,639 Revolutions 13,605 Rituals 13,198 Relations extérieures 12,838 Registers of births, etc 12,565 Retirement 11,921 Renewable energy sources 11,520 Radicalism 11,335 Rates 11,186 Religion and politics 11,091 Reorganization 11,005 Russians 10,996 Remote sensing 10,901 Retail trade 10,839 Registration and transfer 10,798 Recherche 10,466 Rap (Music) 10,329 Romans 10,319 Risk management 10,061 Refuse and refuse disposal 9,874 Reproduction 9,541 Religious education 9,363 Registers 9,337 Regionalism 9,191 Revenue 9,064 Reformed Church 9,060 Radio broadcasting 9,018 Race discrimination 9,003 Riots 8,935 Religion and state 8,928 Recreation 8,802 Radiation 8,696 Robotics 8,461 Reconstruction (1939-1951) 8,379 Rock musicians 8,329 Risk assessment 8,273 Religion and sociology 8,020 Race identity 7,864 Restaurants 7,845 Recruiting, enlistment, etc 7,835 Repentance 7,433 Romanies 7,430 Reclamation of land 7,230 Requiems 7,217 Right and left (Political science) 7,149 Radiography 7,054 Research, Industrial 6,812 Revenge 6,721 Rice 6,626 Russian fiction 6,449 Rule of law 6,421 Romances 6,226 Real estate business 6,171 Relations with women 6,118 Rating of 5,956 Reconstruction (U.S. history, 1865-1877) 5,888 Recruiting 5,839 Race 5,836 Reform 5,755