Duca, Eugenia, and Dorel I. Duca. “Vector Optimization Problems and Approximated Vector Optimization Problems”. Rev. Anal. Numér. Théor. Approx. 39, no. 2 (August 1, 2010): 122–133. Accessed April 11, 2025. https://ictp.acad.ro/jnaat/journal/article/view/2010-vol39-no2-art3.