@article{Hoppe_1984,
    doi = {10.1007/bf00275863},
    url = {https://doi.org/10.1007%2Fbf00275863},
    year = {1984},
    month = {aug},
    publisher = {Springer Science and Business Media {LLC}},
    volume = {20},
    number = {1},
    pages = {91--94},
    author = {Fred M. Hoppe},
    title = {{Polya-like urns and the Ewens' sampling formula}},
    journal = {Journal of Mathematical Biology}
}

@article{Hoppe_1984, doi = {10.1007/bf00275863}, url = {https://doi.org/10.1007%2Fbf00275863}, year = {1984}, month = {aug}, publisher = {Springer Science and Business Media {LLC}}, volume = {20}, number = {1}, pages = {91--94}, author = {Fred M. Hoppe}, title = {{Polya-like urns and the Ewens' sampling formula}}, journal = {Journal of Mathematical Biology} }