Mediterranean Journal of Mathematics
Mediterranean Journal of Mathematics > 2006 > 3 > 3-4 > 549-564
Mediterranean Journal of Mathematics > 2014 > 11 > 2 > 775-787
Mediterranean Journal of Mathematics > 2016 > 13 > 6 > 4497-4507
Mediterranean Journal of Mathematics > 2017 > 14 > 6 > 1-17