TY  - JOUR
AU  - Jianguo Qian
TI  - Enumeration of unlabeled directed hypergraphs
JO  - The electronic journal of combinatorics
PY  - 2013
VL  - 20
IS  - 1
UR  - http://geodesic.mathdoc.fr/articles/10.37236/2766/
DO  - 10.37236/2766
ID  - 10_37236_2766
ER  -