@article{weko_59720_1,
   author	 = "Peter,Eades and Kozo,Sugiyama",
   title	 = "How to Draw a Directed Graph",
   journal	 = "Journal of Information Processing ",
   year 	 = "1991",
   volume	 = "13",
   number	 = "4",
   pages	 = "424--437",
   month	 = "feb"
}