1. Dacorogna, B.: 1982, ‘Weak semicontinuity and weak lower semicontinuity of nonlinear functionals’, Lecture Notes in Mathematics, No. 922, Springer.
2. DiPerna, R.J.: Convergence of approximate solutions to conservation laws, to appear.
3. Tartar, L.C.: 1979, ‘Compensated compactness and applications to partial differential equations’, in Nonlinear Analysis and Mechanics, Heriot-Watt Symposium, IV, pp. 136–192. Research Notes in Mathematics, Pitman.