Carmen Chicone, Marc Jacobs, Bifurcation of Critical Periods for Plane Vector Fields, Transactions of the American Mathematical Society, Vol. 312, No. 2 (Apr., 1989), pp. 433-486 ...

We consider piecewise H¹ functions and vector fields associated with a class of meshes generated by independent refinements and show that they can be effectively analyzed in terms of the number of ...