@article{Merlini_1999,
    doi = {10.1016/s0166-218x(98)00126-7},
    url = {https://doi.org/10.1016%2Fs0166-218x%2898%2900126-7},
    year = {1999},
    month = {jan},
    publisher = {Elsevier {BV}},
    volume = {91},
    number = {1-3},
    pages = {197--213},
    author = {Donatella Merlini and D.G. Rogers and Renzo Sprugnoli and M.Cecilia Verri},
    title = {Underdiagonal lattice paths with unrestricted steps},
    journal = {Discrete Applied Mathematics}
}

@article{Merlini_1999, doi = {10.1016/s0166-218x(98)00126-7}, url = {https://doi.org/10.1016%2Fs0166-218x%2898%2900126-7}, year = {1999}, month = {jan}, publisher = {Elsevier {BV}}, volume = {91}, number = {1-3}, pages = {197--213}, author = {Donatella Merlini and D.G. Rogers and Renzo Sprugnoli and M.Cecilia Verri}, title = {Underdiagonal lattice paths with unrestricted steps}, journal = {Discrete Applied Mathematics} }