@misc{indiciaecb5d16127e1e,
  title = {Bio-augmentation by nitrification with return sludge.},
  author = {S Salem and D H J G Berends and J J Heijnen and M C M Van Loosdrecht},
  year = {2003},
  doi = {10.1016/s0043-1354(02)00550-x},
  url = {https://pubmed.ncbi.nlm.nih.gov/12697224/},
  note = {Source identifier: 12697224}
}