On greedy algorithms with respect to generalized Walsh system
  In this paper we proof that there exists a function f(x) belongs to L^1[0,1] such that a greedy algorithm with regard to generalized Walsh system does not converge to f(x) in L^1[0,1] norm, i.e. the generalized Walsh system is not a quasi-greedy basis in its linear span L^1[0,1]. 
Sergo A. Episkoposian (Yepiskoposyan)
math.FA