@article{douka_1980, 
  title={Kinetics of Manganese Oxidation by Cell-Free Extracts of Bacteria Isolated from Manganese Concretions from Soil}, 
  volume={39}, 
  DOI={10.1128/aem.39.1.74-80.1980}, 
  publisher={American Society for Microbiology}, 
  author={Douka, Catherine E.}, 
  year={1980}
  }