1. Averna, A. andCardinali, T.,Sui concetti di K-convessità (K-concavità) e di K-convessità * (K-concavità*). Riv. Mat. Univ. Parma (4)16 (1990), 311–330.
2. Barbu, V. andPrecupanu, Th.,Convexity and optimization in Banach spaces. Sijthoff & Noordhoff International Publishers, 1978.
3. Deutsch, F. andSinger, I.,On single-valuedness of convex set-valued maps. Set-valued analysis1 (1993), 97–103.
4. Ger, R. andKominek, Z.,Boundedness and continuity of additive and convex functionals. Aequationes Math.37 (1989), 252–258.
5. Kominek, Z.,On additive and convex functionals. Rad. Mat.3 (1987), 267–279.