@inproceedings{bsdsw04,
    author = {Buchin, Kevin and Sousa, Mario Costa and Döllner, Jürgen and Samavati, Faramarz and Walther, Maike},
    booktitle = {4th ICA Mountain Carthography Workshop},
    title = {Illustrating Terrains using Direction of Slope and Lighting},
    year = {2004},
    pages = {259--269},
}