1. 
Structure-aware Halftoning
http://www.cse.cuhk.edu.hk/~ttwong/papers/structurehalftone/structurehalftone.htm

2.
Adaptive Cutaways for Comprehensible Rendering of Polygonal Scenes
http://www.cs.princeton.edu/gfx/pubs/Burns_2008_ACF/index.php

3.
Richness-Preserving Manga Screening
http://www.cse.cuhk.edu.hk/~ttwong/papers/screen/screen.html

4.
Line-art Illustration of Dynamic and Specular Surfaces
http://cg.postech.ac.kr/research/line_art_illustration/

5.
Demarcating Curves for Shape Illustration
http://mis.hevra.haifa.ac.il/~ishimshoni/pub.htm