Global approximation of CR functions on Bloom-Graham model graphs in   $C^n$
  We define a class of generic CR submanifolds of $C^n$ of real codimension $d$, with $d$ in $1, ..., n-1$, called the Bloom-Graham model graphs, whose graphing functions are partially decoupled in their dependence on the variables in the real directions. We prove a global version of the Baouendi-Treves CR approximation theorem, for Bloom-Graham model graphs with a polynomial growth assumption on their graphing functions. 
Albert Boggess, Daniel Jupiter