Religious aspects 227,315 Research 200,096 Religion 154,836 Relations 124,093 Railroads 84,161 Roads 65,607 Race relations 58,448 Religious life 45,936 Russian literature 41,016 Regional planning 40,836 Russian language 35,316 Rural conditions 34,953 Real property 34,541 Rock music 33,782 Religious life and customs 32,855 Reference 32,060 Rhetoric 30,922 Refugees 30,869 Rural development 29,035 Rites and ceremonies 28,231 Rules and practice 24,885 Regimental histories 24,184 Rehabilitation 24,019 Reformation 21,972 Racism 20,870 Readers 20,329 RELIGION 20,259 Reading 19,852 Revolutionaries 18,798 Radio 16,710 Russian poetry 15,443 Roman law 14,960 Religions 14,774 Russian 14,680 Rabbis 14,640 Romanticism 14,346 Responsa 14,186 Rivers 13,922 Rare books 13,900 Representative government and representation 13,866 Renaissance 13,713 Religion and science 13,641 Revolutions 13,609 Rituals 13,202 Relations extérieures 12,888 Registers of births, etc 12,570 Retirement 11,925 Renewable energy sources 11,545 Radicalism 11,348 Rates 11,190 Religion and politics 11,095 Reorganization 11,006 Russians 11,002 Remote sensing 10,909 Retail trade 10,839 Registration and transfer 10,805 Recherche 10,498 Romans 10,334 Rap (Music) 10,333 Risk management 10,066 Refuse and refuse disposal 9,888 Reproduction 9,541 Religious education 9,355 Registers 9,336 Regionalism 9,195 Revenue 9,063 Reformed Church 9,060 Race discrimination 9,027 Radio broadcasting 9,027 Riots 8,937 Religion and state 8,931 Recreation 8,808 Radiation 8,697 Robotics 8,472 Reconstruction (1939-1951) 8,380 Rock musicians 8,333 Risk assessment 8,280 Religion and sociology 8,024 Race identity 7,875 Restaurants 7,854 Recruiting, enlistment, etc 7,837 Romanies 7,431 Repentance 7,429 Reclamation of land 7,230 Requiems 7,217 Right and left (Political science) 7,157 Radiography 7,054 Research, Industrial 6,812 Revenge 6,728 Rice 6,628 Russian fiction 6,451 Rule of law 6,429 Romances 6,219 Real estate business 6,173 Relations with women 6,124 Rating of 5,958 Reconstruction (U.S. history, 1865-1877) 5,865 Race 5,843 Recruiting 5,839 Reform 5,747