Algorithm 652: HOMPACK: a suite of codes for globally convergent homotopy algorithms. - Layne T. Watson; Stephen C. Billups; Alexander P. Morgan (ACM Trans. Math. Softw., 1987)

QPCOMP: A quadratic programming based solver for mixed complementarity problems. - Stephen C. Billups; Michael C. Ferris (Math. Program., 1996)

Convergence of an Infeasible Interior-Point Algorithm from Arbitrary Positive Starting Points. - Stephen C. Billups; Michael C. Ferris (SIAM J. Optim., 1996)

A Comparison of Large Scale Mixed Complementarity Problem Solvers. - Stephen C. Billups; Steven P. Dirkse; Michael C. Ferris (Comput. Optim. Appl., 1997)

Solutions to Affine Generalized Equations Using Proximal Mappings. - Stephen C. Billups; Michael C. Ferris (Math. Oper. Res., 1999)

Improving the robustness of descent-based methods for semismooth equations using proximal perturbations. - Stephen C. Billups (Math. Program., 2000)

A Homotopy-Based Algorithm for Mixed Complementarity Problems. - Stephen C. Billups (SIAM J. Optim., 2002)

A Probability-One Homotopy Algorithm for Nonsmooth Equations and Mixed Complementarity Problems. - Stephen C. Billups; Layne T. Watson (SIAM J. Optim., 2002)

Minimum-Support Solutions for Radiotherapy Planning. - Stephen C. Billups; Janine M. Kennedy (Ann. Oper. Res., 2003)

Probability-one homotopy maps for mixed complementarity problems. - Kapil Ahuja; Layne T. Watson; Stephen C. Billups (Comput. Optim. Appl., 2008)

Identifying significant temporal variation in time course microarray data without replicates. - Stephen C. Billups; Margaret C. Neville; Michael Rudolph 004; Weston Porter; Pepper Schedin (BMC Bioinform., 2009)

Optimization in Medical Imaging. - Stephen C. Billups (Encyclopedia of Optimization, 2009)

Solving the canonical dual of box- and integer-constrained nonconvex quadratic programs via a deterministic direct search algorithm. - David Yang Gao; Layne T. Watson; David R. Easterling; William I. Thacker; Stephen C. Billups (Optim. Methods Softw., 2013)

Derivative-Free Optimization of Expensive Functions with Computational Error Using Weighted Regression. - Stephen C. Billups; Jeffrey Larson 001; Peter A. Graf (SIAM J. Optim., 2013)

A Globally Convergent Probability-One Homotopy for Linear Programs with Linear Complementarity Constraints. - Layne T. Watson; Stephen C. Billups; John E. Mitchell 001; David R. Easterling (SIAM J. Optim., 2013)

Stochastic derivative-free optimization using a trust region framework. - Jeffrey Larson 001; Stephen C. Billups (Comput. Optim. Appl., 2016)

MDTri: robust and efficient global mixed integer search of spaces of multiple ternary alloys. - Peter A. Graf; Stephen C. Billups (Comput. Optim. Appl., 2017)

Dynamic System Diversification for Securing Cloud-based IoT Subnetworks. - Hussain M. J. Almohri; Layne T. Watson; David Evans 001; Stephen C. Billups (ACM Trans. Auton. Adapt. Syst., 2022)