The Critical Point of Unoriented Random Surfaces with a Non-Even   Potential
  The discrete model of the real symmetric one-matrix ensemble is analyzed with a cubic interaction. The partition function is found to satisfy a recursion relation that solves the model. The double-scaling limit of the recursion relation leads to a Miura transformation relating the contributions to the free energy coming from oriented and unoriented random surfaces. This transformation is the same kind as found with a cuartic interaction. 
M.A. Mart\'in-Delgado