@article{nikora2004water,
  title={Water-worked gravel surfaces: High-order structure functions at the particle scale},
  author={Nikora, Vladimir, and Walsh, Jeremy},
  journal={Water Resources Research},
  volume={40},
  number={12},
  year={2004},
  publisher={Wiley Online Library}
}

author={Nikora, Vladimir, and Walsh, Jeremy},
author={Nikora, Vladimir and, Walsh, Jeremy},
author={Nikora, Vladimir and Walsh, Jeremy},
author={Nikora, Vladimir and Walsh, Jeremy},