1 Subjects: “...gravitational lensing...”

2 Subjects: “...gravitational force...”

3 Subjects: “...hybrid gravitational with fire fly algorithm...”

4 Subjects: “...gravitation...”

5 Subjects: “...gravitational effects...”

6 Subjects: “...self-gravitation...”

7 Subjects: “...gravitational search algorithm...”

8 Subjects: “...gravitational...”

9 Subjects: “...gravitational waves...”

10 Subjects: “...gravitational segregation...”

11 Subjects: “...gravitational force...”

12 Subjects: “...gravitational search algorithm...”

13 Subjects: “...gravitational waves...”

14 Subjects: “...gravitational waves...”

15 Subjects: “...equations of motion in gravitational theory...”

16 Subjects: “...gravitational degree...”