The Jenkins-Serrin problem for constant mean curvature graphs in the   Heisenberg space $\mathbf{Nil_3}(\tau)$
  In this paper we find functions over bounded domains in the 2-dimensional Euclidean space, whose graphs (in the Heisenberg space) has constant mean curvature different from zero and taking on (possibly) infinite boundary values over the boundary of the domain. 
Carlos Penafiel
math.DG