TY  - BOOK
AU  - Harary,Frank
AU  - Norman,Robert Z.
AU  - Cartwright,Dorwin
TI  - Structural models: an introduction to the theory of directed graphs 
U1  - 510.83 
PY  - 1965///
CY  - New York
PB  - Wiley
KW  - Social sciences
KW  - Mathematical models
KW  - Mathematics
KW  - Philosophy
N1  - Includes index; Bibliography: p. 392-395
ER  -