@article{pires_guerra-sommer_2011,  title={Growth ring analysis of fossil coniferous woods from early cretaceous of Araripe Basin (Brazil)},  volume={83},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652011005000005},  DOI={10.1590/S0001-37652011005000005},  number={2},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={Pires, Etiene F. and Guerra-Sommer, Margot},  year={2011},  month={Jun},  pages={409–423} }