Công bố năm 2004
1. Hoàng Xuân Phú, Approximate Fixed-Point Theorems for Discontinuous Mappings, Numerical Functional Analysis and Optimization, Vol. 25, No. 1&2, pp. 119-136, 2004
2. Hoàng Xuân Phú, Is Invexity Weaker than Convexity?, Vietnam Journal of Mathematics, Vol. 32, No. 1, pp. 87-94, 2004
3. Hoàng Xuân Phú, On some Badly-Solved Problems with Invexity, Acta Mathematica Vietnamica, Vol. 29, No. 1, pp. 89-106, 2004.
4. Hoàng Xuân Phú, On a Necessary Optimality Condition with Invexity, Acta Mathematica Vietnamica, Vol. 29, No. 2, pp. 141-148, 2004
