Stabilization of bilinear mixed finite elements for tetrahedra with enhanced interpolation using volume and area bubble functions
R. Mahnken, I. Caylak, International Journal for Numerical Methods in Engineering (2007) 377–413.

Two mixed finite element formulations with area bubble functions for tetrahedral elements
R. Mahnken, I. Caylak, G. Laschet, Computer Methods in Applied Mechanics and Engineering (2007) 1147–1165.