Multidimensional Binning Techniques for a Two Parameter Trilinear Gauge   Coupling Estimation at LEP II
  This paper describes two generalization schemes of the Optimal Variables technique in estimating simultaneously two Trilinear Gauge Couplings. The first is an iterative procedure to perform a 2-dimensional fit using the linear terms of the expansion of the probability density function with respect to the corresponding couplings, whilst the second is a clustering method of probability distribution representation in five dimensions. The pair production of W's at 183 GeV center of mass energy, where one W decays leptonically and the other hadronically, was used to demonstrate the optimal properties of the proposed estimation techniques. 
G. K. Fanourakis, D. Fassouliotis, A. Leisos, N. Mastroyiannopoulos   and S. E. Tzamarias