@article{h2004characteristics,
  title = {Characteristics of residual soils in Singapore as formed by weathering}
  author = {H. Rahardjoa, K.K. Aungb
, E.C. Leongc, R.B. Rezaurd,},
  url = {https://pdfs.semanticscholar.org/0341/de394e927c18d13206083ae6a79a6d01ebc8.pdf},
  doi = {doi:10.1016},
  year = {2004}
}