Encyclopedias, Almanacs, Transcripts, and Maps
- Regulation and Rates for Electricity
- Regulatory Review
- Reguly, Antal
- Reilly, William Kane (1940 – ) American Conservationist and Environmental Protection Agency Administrator
- Reimarus, Hermann Samuel
- Reinach, Salomon
- Reines, Yitsḥaq Yaʿaqov
- Reiyūkai Kyōdan
- relative density
- Relics
- Relict Species
- Religion and the Environment
- Religionsgeschichtliche Schule
- Religious Broadcasting
- Religious Communities
- Religious Communities: Christian Religious Orders
- Religious Communities: Religion, Community, and Society
- Religious Diversity
- Religious Education
- Remediation