1 Subjects: “...validation...”

2 Subjects: “...experimental validation...”

3 Subjects: “...in-situ validation...”

4 Subjects: “...cross-validation...”

5 Subjects: “...model validation...”

6 Subjects: “...dataset validation...”

7 Subjects: “...airborne validation of satellite data...”

8 Subjects: “...validation...”

9 Subjects: “...validation...”

10 Subjects: “...validation studies...”

11 Subjects: “...cluster validity indices...”