[1]  Chueh K N, Conley C C, Smoller J A. Positive invariant regions for systems of nonlinear diffusion equations.
Indiana Univ Math J, 1977, 26: 372–411

[2] Chen G -Q, Levermore C D, Liu T -P. Hyperbolic conservation laws with stiff relaxation terms and entropy.
Comm Pure Appl Math, 1994, 47: 787–830

[3] DiPerna R J. Convergence of approximate solutions to conservation laws. Arch Rat Mech Anal, 1983, 82:
27–70

[4] Lu Y -G. Singular Limits of Stiff Relaxation and Dominant Diffusion for Nonlinear Systems. J Diff Equs,
2002, 179(2): 687–713

[5] Lu Y -G. Hyperboilc Conservation Laws and the Compensated Compactness Method. Vol 128. New York:
Chapman and Hall, CRC Press, 2003

[6] Natalini R. Convergence to equilibrium for the relaxation approximations of conservation laws. Comm
Pure Appl Math, 1996, 49: 795–823