@article{Salomaa_1990, title={Decision problems arising from knapsack transformations}, volume={9}, url={https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3385}, number={4}, journal={Acta Cybernetica}, author={Salomaa, Arto}, year={1990}, month={Jan.}, pages={419-440} }