De Abreu N.Cvetković, DraganGutman I.Nikiforov V.2021-04-202021-04-2020100024-3795https://scidar.kg.ac.rs/handle/123456789/10251restrictedAccesscontributionToPeriodical10.1016/j.laa.2009.11.0182-s2.0-77149163485