@article{olfos_goldrine_estrella_2014,  title={Teachers' pedagogical content knowledge and its relation with students' understanding},  volume={19},  ISSN={1413-2478},  url={https://doi.org/10.1590/S1413-24782014000900006},  DOI={10.1590/S1413-24782014000900006},  number={59},  journal={Revista Brasileira de Educação},  publisher={ANPEd - Associação Nacional de Pós-Graduação e Pesquisa em Educação},  author={Olfos, Raimundo and Goldrine, Tatiana and Estrella, Soledad},  year={2014},  month={Oct},  pages={913–944} }