1 Subjects: “...cost...”

2 Subjects: “...cost-efficiency ratio...”

3 Subjects: “...least-cost modeling...”

4 Subjects: “...pollution costs...”

5 Subjects: “...costs...”

6 Subjects: “...costs...”

7 Subjects: “...variable cost...”

8 Subjects: “...costing...”

9 Subjects: “...transportation costs...”

10 Subjects: “...cost analysis...”

11 Subjects: “...prime machining costs...”

12 Subjects: “...low-cost polymer donor...”

13 Subjects: “...benefit-cost ratio...”

14 Subjects: “...cost-optimal analysis...”

15 Subjects: “...cost analysis...”

16 Subjects: “...production cost...”

17 Subjects: “...ecological costs...”

18 Subjects: “...ecological costs...”

19 Subjects: “...ecological costs...”