@article{ryu_lee_2013, 
  title={The Characteristics of Retention and Evapotranspiration in the Extensive Greening Module of Sloped and Flat Rooftops}, 
  volume={41}, 
  DOI={10.9715/kila.2013.41.6.107}, 
  publisher={Korean Institute of Landscape Architecture}, 
  author={Ryu and Lee}, 
  year={2013}, 
  month={Dec}
  }