Testing extendability for partial chirotopes is np-complete. - Falk Tschirschnitz (CCCG, 2001)

One line and n points. - Bernd Gärtner; József Solymosi; Falk Tschirschnitz; Emo Welzl; Pavel Valtr 001 (STOC, 2001)

Grid Orientations, (d, d+2)-Polytopes, and Arrangements of Pseudolines. - Stefan Felsner; Bernd Gärtner; Falk Tschirschnitz (Discret. Comput. Geom., 2005)