Dispersionless (3+1)-dimensional integrable hierarchies
  In the present paper we introduce a multi-dimensional version of the R-matrix approach to the construction of integrable hierarchies. Applying this method to the case of the Lie algebra of functions with respect to the contact bracket, we construct integrable hierarchies of (3+1)-dimensional dispersionless systems of the type recently introduced by one of us in arXiv:1401.2122. 
Maciej Blaszak and Artur Sergyeyev
nlin.SI