@article{gullo_lopretto_2021,  title={Testisacs microanatomy and spermatogenesis of <i>Helobdella simplex</i> (Hirudinida: Glossiphoniidae)},  volume={38},  ISSN={1984-4670},  url={https://doi.org/10.1590/S1984-4689.v38.e21019},  DOI={10.1590/S1984-4689.v38.e21019},  journal={Zoologia (Curitiba)},  publisher={Sociedade Brasileira de Zoologia},  author={Gullo, Bettina S. and Lopretto, Estela C.},  year={2021},  pages={e21019} }