On the Number of Connected Components of the Relative Closure of a Semi-Pfaffian Family. - Andrei Gabrielov; Thierry Zell (Algorithmic and Quantitative Aspects of Real Algebraic Geometry in Mathematics and Computer Science, 2001)

Topology of Definable Hausdorff Limits. - Thierry Zell (Discret. Comput. Geom., 2005)

On Projections of Semi-Algebraic Sets Defined by Few Quadratic Inequalities. - Saugata Basu; Thierry Zell (Discret. Comput. Geom., 2008)

Topological Complexity of the Relative Closure of a Semi-Pfaffian Couple. - Thierry Zell (Discret. Comput. Geom., 2008)

Polynomial Hierarchy, Betti Numbers, and a Real Analogue of Toda's Theorem. - Saugata Basu; Thierry Zell (Found. Comput. Math., 2010)