[1] Capogna L, Garofalo N. Regularity of minimizers of the calculus of variations in Carnot groups via hypoellipticity of systems of Hormander type[J]. J European Math Soc, 2003, 5: 1-40.
[2] Shores E. Hypoellipticity for linear degenerate elliptic systems in Carnot groups and applications[R]. Fayetteville:University of Arkansas, arXiv: mathAP/050256, 2005.
[3] Wang J, Niu P. Optimal partial regularity for weak solutions of nonlinear sub-elliptic systems in Carnot groups[J]. Nonlinear Analysis, 2010, 72: 4162-4187.
[4] Wang J, Liao D. Optimal partial regularity for sub-elliptic systems with sub-quadratic growth in Carnot groups[J]. Nonlinear Analysis, 2012, 75:2499-2519.
[5] Zhu M, Bramanti M, Niu P. Interior HW1, p estimates for divergence degenerate elliptic systems in Carnot groups[J]. J Math Anal Appl, 2013, 399: 442-458.
[6] Wang L. A geometric approach to the Calderon-Zygmund estimates[J]. Acta Mathematica Sinica, 2003, 19: 381-396.
[7] Byun S, Wang L. Elliptic equations with BMO coefficients in Reifenberg domains[J]. Comm Pure and Appl Math, 2004, 57: 1283-1310.
[8] Byun S, Wang L. Gradient estimates for elliptic systems in non-smooth domains[J]. Math Ann, 2008, 241: 629-650.
[9] Mengesha T, Phuc N C. Weighted and regularity estimates for nonlinear equations on Reifenberg flat domains[J]. J Diff Eqs, 2011, 250: 2485-2507.
[10] Folland G B. Subelliptic estimates and function spaces on nilpotent Lie groups[J]. Ark Mat, 1975, 13: 161-207.
[11] Bonfiglioli A, Lanconelli E, Uguzzoni F. Stratified Lie groups and potential theory for their sub-Laplacians[M]. Springer Monographs in Mathematics. Berlin:Springer, 2007.
[12] Stein E M. Harmonic analysis: real-variable methods, orthogonality, and oscillatory integrals[M]. Princeton Mathematical Series, 43. Monographs in Harmonic Analysis, Ⅲ. Princeton, NJ: Princeton University Press, 1993.
[13] Bramanti M, Brandolini L. Lp-estimates for nonvariational hypoelliptic operators with VMO coefficients[J]. Trans Amer Math Soc, 2000, 352: 781-822.
[14] Bramanti M, Brandolini L. Estimates of BMO type for singular integrals on spaces of homogeneous type and applications to hypoelliptic PDES[J]. Revista Matematica Iberoamericana, 2005, 21: 511-556.
[15] Coifman R, Weiss G. Analyse harmonique non-commutative sur certains espaces homogènes[M]. Lecture Notes in Mathematics, 242. Springer-Verlag, Berlin-Heidelberg-New York, 1971.
[16] Maclas R, Segovia C. A well behaved quasi-distance for spaces of homogeneous type[J]. Trabajos de Matematica, Inst Argentino Mat, 1981, 32: 1-18.
[17] Grafakos L. Classical and modern Fourier analysis[M]. Upper Saddle River NJ: Pearson Education Inc/Prentice Hall, 2004. |