@article{langler_2001,  title={A structural bridge between alternant and non-alternant hydrocarbons},  volume={24},  ISSN={0100-4042},  url={https://doi.org/10.1590/S0100-40422001000300021},  DOI={10.1590/S0100-40422001000300021},  number={3},  journal={Química Nova},  publisher={Sociedade Brasileira de Química},  author={Langler, Richard Francis},  year={2001},  month={May},  pages={416–418} }