@ARTICLE{Sierociuk_D._Duality_2014, author={Sierociuk, D. and Twardy, M.}, volume={62}, number={No 4}, journal={Bulletin of the Polish Academy of Sciences Technical Sciences}, pages={809-815}, howpublished={online}, year={2014}, title={Duality of variable fractional order difference operators and its application in identification}, URL={http://www.czasopisma.pan.pl/Content/84036/PDF/24_paper.pdf}, doi={10.2478/bpasts-2014-0089}, }