From Singularity Theory to Finiteness of Walrasian Equilibria
Sofia Castro, Sami Dakhlia, Peter Gothen
Mathematical Social Sciences, vol. 66, 2013, p. 169-175.

Direct Perturbations of Aggregate Excess Demand
Sofia Castro, Sami Dakhlia, Peter Gothen
Journal of Mathematical Economics, vol. 46, 2010, p. 562-571.