Strong law of large numbers for optimal points. Denkowska, Anna (2005) Zeszyty Naukowe Uniwersytetu Jagiellońskiego. Universitatis Iagellonicae Acta Mathematica
The sums of closed subspaces in a topological linear space Jan Hamhalter (1989) Acta Universitatis Carolinae. Mathematica et Physica
Two fixed-point theorems for mappings satisfying a general contractive condition of integral type in the modular space. Beygmohammadi, Maryam, Razani, Abdolrahman (2010) International Journal of Mathematics and Mathematical Sciences