1 Subjects: “...partial differential equation...”

2 Subjects: “...partial differential equations...”

3 Subjects: “...partial differential equation...”

4 Subjects: “...partial differential equations...”

5 Subjects: “...partial differential equations...”

6 Subjects: “...partial differential equation...”

7 Subjects: “...partial differential equations...”

8 “... and/or isoperimetric constraints involving first- and second-order partial differential equations....”

9 “... and/or isoperimetric constraints involving first- and second-order partial differential equations....”

10 “.../partial differential equations, etc. Their applications include crack propagation, acoustic analysis...”