1 Retraction to: Mediterr. J. Math. (2020) 17:37 https://doi.org/10.1007/s00009-019-1471-2

The Editor-in-Chief has retracted this Article because of a significant overlap with another publication [1] by different authors. This was brought to the Editor’s attention by the corresponding author. Author Vahid Hedayati agrees to this retraction. Authors Mohammad Esmael Samei and Ghorban Khalilzadeh Ranjbar do not agree to this retraction.