On the multiplicity of ( X a - Y b , X c - Y d ) . Boďa, E.; Országhová, D. — 1998 Acta Mathematica Universitatis Comenianae. New Series
On standard basis and multiplicity of ( X a - Y b , X c - Y d ) . Boďa, E.; Fernbauer, R. — 2003 Acta Mathematica Universitatis Comenianae. New Series
On the minimal reduction and multiplicity of ( X m , Y n , X k Y l , X r Y s ) . Boďa, E.; Országhová, D.; Solčan, Š. — 1993 Acta Mathematica Universitatis Comenianae. New Series