When is rounding allowed in integer nonlinear optimization? - Ruth Hübner; Anita Schöbel (Eur. J. Oper. Res., 2014)

Ellipsoid Bounds for Convex Quadratic Integer Programming. - Christoph Buchheim; Ruth Hübner; Anita Schöbel (SIAM J. Optim., 2015)

Norm bounds and underestimators for unconstrained polynomial integer minimization. - Sönke Behrends; Ruth Hübner; Anita Schöbel (Math. Methods Oper. Res., 2018)