Discussiones Mathematicae - General Algebra and Applications
Discussiones Mathematicae - General Algebra and Applications > 2008 > 28 > 1 > 11-27
Discussiones Mathematicae - General Algebra and Applications > 2013 > 33 > 1 > 57-71
Discussiones Mathematicae - General Algebra and Applications > 2016 > 36 > 1 > 45-58