Gao Jia, Xiao-Ping Yang, Euler equations and approximations for the minimingers of Heisenberg target, Nonlinear Analysis, 67 (2007), 2690–2698.
Gao Jia, Regularities and singularities of the energy minimizers of the Heisenberg groups targets, Acta Mathematics Scientia, 23, 4 (2003), 39–45.
Gao Jia, Xiao-Ping Yang, Jinde Cao, The Holder continuities of the maps in $W^{1,p}(\Omega,\bold H^n)$, Appl. Math. And Comput., 149, 2 (2003), 507–518.
Gao Jia, Xiao-Ping Yang,Some remarks about the Heisenberg group, J. of PDEs, 15, 3 (2002), 39–45.
Gao Jia, Xiao-Ping Yang, BMO Spaces and John-Nirenberg Estimates for the Heisenberg Group Targets, J. of PDEs, 16, 3 (2003), 204–210.
