To cite webchem in publications use:

Eduard Szöcs et al. (2015). webchem: zenodo release. Zenodo. 10.5281/zenodo.33823

Corresponding BibTeX entry:

  @Manual{,
    title = {{webchem}: retrieve chemical information from the web},
    author = {Eduard Szöcs},
    journal = {Zenodo},
    year = {2015},
    url = {http://dx.doi.org/10.5281/zenodo.33823},
  }