Phase Transition Strength through Densities of General Distributions of   Zeroes
  A recently developed technique for the determination of the density of partition function zeroes using data coming from finite-size systems is extended to deal with cases where the zeroes are not restricted to a curve in the complex plane and/or come in degenerate sets. The efficacy of the approach is demonstrated by application to a number of models for which these features are manifest and the zeroes are readily calculable. 
W. Janke, D.A. Johnston, R. Kenna