| Radio frequencies (1) | Radio frequency identification (1) | Radio frequency Identification (RFID) (1) |
| real-time strategy (1) | Real-time strategy game (1) | real-time strategy games (1) |
| Recommendation Systems (1) | Recommendations of Sets of Items (1) | Recommender systems (1) |
| Redundancy (1) | redundant publications (1) | Regression case based reasoning (1) |
| Reinforcement learning (1) | Research policy (1) | Resource description framework (1) |
| review (1) | Review Cycles (1) | review quality (1) |
| Reviewers (1) | RFID (2) | RFID project (1) |
| Rule-based reasoning (1) | Rules engine (1) | Runtime (1) |