Extracting Classical Correlations from a Bipartite Quantum System
  In this paper we discuss the problem of splitting the total correlations for a bipartite quantum state described by the Von Neumann mutual information into classical and quantum parts. We propose a measure of the classical correlations as the difference between the Von Neumann mutual information and the relative entropy of entanglement. We compare this measure with different measures proposed in the literature. 
S. Hamieh, J. Qi, D. Siminovitch, and M. K. Ali