TY  - BOOK
AU  - Harary, Frank.
AU  - Cartwright, Dorwin. 
AU  - Norman, Robert Z.
TI  - Structural models : : an introduction to the theory of directed graphs 
SN  - 9780471351306 (hbk.)
U1  - 511.5 
PY  - 1965///
CY  - New York
PB  - Wiley
KW  - Social sciences
KW  - Mathematical models
N1  - Includes glossary and index
ER  -