@article{steffen2015planetary,
  title = {Planetary boundaries: Guiding human development on a changing planet}
  author = {Steffen, W. and Richardson, K. and Rockstrom, J. and Cornell, S. E. and Fetzer, I. and Bennett, E. M. and Biggs, R. and Carpenter, S. R. and de Vries, W. and de Wit, C. A. and Folke, C. and Gerten, D. and Heinke, J. and Mace, G. M. and Persson, L. M. and Ramanathan, V. and Reyers, B. and Sorlin, S.},
  journal = {Science},
  url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1259855},
  year = {2015}
}