Iskander Aliev Gennadiy Averkov Jesús A. De Loera Timm Oertel Sparse representation of vectors in lattices and semigroups. 519-546 2022 192 Math. Program. 1 https://doi.org/10.1007/s10107-021-01657-8 db/journals/mp/mp192.html#AlievALO22