Media type: E-Article Title: Graph Theory and Algorithms: Dividing a system into almost unidirectional blocks Contributor: Mayeda, Wataru imprint: Springer Berlin Heidelberg, 1981 Published in: Graph Theory and Algorithms Language: Not determined DOI: 10.1007/3-540-10704-5_1 ISSN: 0302-9743; 1611-3349 Origination: Footnote: