@article{small,
  title={Exceptional preservation of photosynthetic organisms in silicified carbonates and silicified peats},
  author={A H Knoll},
  journal={Philosophical Transactions of the Royal Society: Biological Sciences},
  volume={311},
  pages={111-122},
  year={1985},
  doi={10.1098/rstb.1985.0143}
}