@article{OSSJ09,
  author      = {Luke Olsen and 
                 Faramarz F. Samavati and 
                 Mario Costa Sousa and 
                 Joaquim A. Jorge},
  title       = {Sketch-based modeling: A survey},
  journal     = {Computers {\&} Graphics},
  issn        = {0097-8493},
  volume      = {33},
  number      = {1},
  month       = {Feb},  
  year        = {2009},      
  pages       = {85-103},
  doi         = {http://dx.doi.org/10.1016/j.cag.2008.09.013},
  url         = {http://www.sciencedirect.com/science/article/B6TYG-4TPF4GK-2/2/bc4d1162dc5b79a3887fd969b736dd3e}
}