Religious aspects 227,618 Research 200,264 Religion 155,212 Relations 124,212 Railroads 84,231 Roads 65,628 Race relations 58,511 Religious life 45,977 Russian literature 41,066 Regional planning 40,855 Russian language 35,332 Rural conditions 34,980 Real property 34,582 Rock music 33,817 Religious life and customs 32,889 Reference 32,053 Rhetoric 30,952 Refugees 30,926 Rural development 29,047 Rites and ceremonies 28,245 Rules and practice 24,890 Regimental histories 24,205 Rehabilitation 24,041 Reformation 21,975 Racism 20,914 Readers 20,329 RELIGION 20,240 Reading 19,857 Revolutionaries 18,827 Radio 16,725 Russian poetry 15,500 Roman law 14,966 Religions 14,772 Russian 14,679 Rabbis 14,670 Romanticism 14,342 Responsa 14,197 Rivers 13,938 Rare books 13,910 Representative government and representation 13,872 Renaissance 13,691 Religion and science 13,648 Revolutions 13,610 Relations extérieures 13,284 Rituals 13,225 Registers of births, etc 12,574 Retirement 11,992 Renewable energy sources 11,605 Radicalism 11,355 Revenue 11,347 Rates 11,191 Religion and politics 11,101 Reorganization 11,018 Russians 11,017 Remote sensing 10,916 Retail trade 10,842 Registration and transfer 10,806 Recherche 10,615 Rap (Music) 10,343 Romans 10,242 Risk management 10,072 Refuse and refuse disposal 9,894 Reproduction 9,537 Religious education 9,365 Registers 9,336 Regionalism 9,210 Reformed Church 9,063 Radio broadcasting 9,051 Race discrimination 9,039 Recreation 8,951 Riots 8,947 Religion and state 8,936 Radiation 8,696 Robotics 8,496 Reconstruction (1939-1951) 8,379 Rock musicians 8,342 Risk assessment 8,282 Religion and sociology 8,023 Restaurants 8,007 Race identity 7,899 Recruiting, enlistment, etc 7,839 Romanies 7,444 Repentance 7,437 Reclamation of land 7,234 Requiems 7,226 Right and left (Political science) 7,176 Radiography 7,053 Research, Industrial 6,811 Revenge 6,749 Rice 6,629 Russian fiction 6,455 Rule of law 6,434 Romances 6,239 Real estate business 6,177 Relations with women 6,118 Rating of 5,958 Reconstruction (U.S. history, 1865-1877) 5,871 Race 5,850 Recruiting 5,840 Reform 5,730