TY  - GEN
AU  - Harary, Frank
AU  - Cartwright, Dorwin
AU  - Norman, Robert Z.
TI  - Structural models: an introduction to the theory of directed graphs 
SN  - B013PRHOG2
U1  - 301.8 
PY  - 1965///
CY  - New York
PB  - John Wiley & Sons
KW  - Social sciences - Mathematical models
ER  -