VXQR: derivative-free unconstrained optimization based on QR factorizations. - Arnold Neumaier; Hannes Fendl; Harald Schilly; Thomas Leitner (Soft Comput., 2011)

Certificates of infeasibility via nonsmooth optimization. - Hannes Fendl; Arnold Neumaier; Hermann Schichl (J. Glob. Optim., 2017)