1 Subjects: “...energy efficiency...”

2 Subjects: “...Combustion efficiency...”

3 Subjects: “...water efficiency...”

4 Subjects: “...efficiency...”

5 Subjects: “...technical efficiency...”

6 Subjects: “...energy efficiency...”

7 Subjects: “...technical and super-efficiencies...”

8 Subjects: “...carbon emissions efficiency...”

9 Subjects: “...efficiency...”

10 Subjects: “...efficient market hypothesis...”

11 Subjects: “...energy-efficient...”

12 Subjects: “...eco-efficiency...”

13 Subjects: “...firm efficiency...”

14 Subjects: “...asymptotic efficiency...”

15 Subjects: “...super-efficient SBM...”

16 Subjects: “...PCS efficiency...”

17 Subjects: “...PCS efficiency...”

18 Subjects: “...high computational efficiency...”

19 Subjects: “...high computational efficiency...”