Discussiones Mathematicae - General Algebra and Applications
Discussiones Mathematicae - General Algebra and Applications > 2004 > 24 > 1 > 31-42
Discussiones Mathematicae - General Algebra and Applications > 2005 > 25 > 2 > 155-163
Discussiones Mathematicae - General Algebra and Applications > 2004 > 24 > 1 > 31-42
Discussiones Mathematicae - General Algebra and Applications > 2005 > 25 > 2 > 155-163