Religious aspects 227,995 Research 200,542 Religion 155,385 Relations 124,369 Railroads 84,292 Roads 65,644 Race relations 58,636 Religious life 46,044 Russian literature 41,115 Regional planning 40,886 Russian language 35,358 Rural conditions 35,009 Real property 34,631 Rock music 33,856 Religious life and customs 32,944 Reference 32,057 Rhetoric 30,999 Refugees 30,990 Rural development 29,069 Rites and ceremonies 28,269 Rules and practice 24,939 Regimental histories 24,226 Rehabilitation 24,069 Reformation 21,984 Racism 20,981 Readers 20,330 RELIGION 20,240 Reading 19,878 Revolutionaries 18,869 Radio 16,735 Russian poetry 15,518 Roman law 14,975 Religions 14,782 Russian 14,700 Rabbis 14,698 Romanticism 14,352 Responsa 14,215 Rivers 13,952 Rare books 13,931 Representative government and representation 13,885 Renaissance 13,703 Religion and science 13,656 Revolutions 13,629 Relations extérieures 13,485 Rituals 13,243 Registers of births, etc 12,586 Retirement 12,001 Renewable energy sources 11,634 Radicalism 11,380 Revenue 11,367 Rates 11,193 Religion and politics 11,120 Russians 11,032 Reorganization 11,021 Remote sensing 10,920 Retail trade 10,849 Registration and transfer 10,815 Recherche 10,690 Rap (Music) 10,362 Romans 10,246 Risk management 10,086 Refuse and refuse disposal 9,904 Reproduction 9,550 Religious education 9,375 Registers 9,336 Regionalism 9,217 Reformed Church 9,069 Race discrimination 9,067 Radio broadcasting 9,059 Recreation 8,963 Riots 8,956 Religion and state 8,954 Radiation 8,700 Robotics 8,525 Reconstruction (1939-1951) 8,385 Rock musicians 8,350 Risk assessment 8,293 Religion and sociology 8,036 Restaurants 8,019 Race identity 7,927 Recruiting, enlistment, etc 7,842 Romanies 7,453 Repentance 7,440 Reclamation of land 7,238 Requiems 7,229 Right and left (Political science) 7,200 Radiography 7,059 Research, Industrial 6,808 Revenge 6,764 Rice 6,631 Russian fiction 6,466 Rule of law 6,441 Romances 6,247 Real estate business 6,180 Relations with women 6,125 Rating of 5,960 Reconstruction (U.S. history, 1865-1877) 5,872 Race 5,856 Recruiting 5,843 Reform 5,731