1 Introduction  
1.1 Top-k approach  
1.2 Skyline approach  

2 Flexible/Restricted Skylines  
2.1 Restricted Skyline, ND and PO  
2.2 Trade-off Skyline  
2.3 Applications of ρ-dominance: ORD and ORU  
2.4 Top-K dominating queries on skyline groups  
2.7 Regret minimization  

3 Comparison with vanilla approaches and conclusions  
3.1 Restricted Skyline, ND and PO  
3.2 Trade-off Skyline  
3.3 Applications of ρ-dominance: ORD and ORU  
3.4 Top-K dominating queries on skyline groups  
3.6 Skyline ordering  
3.7 Regret minimization  
3.8 Conclusions