TY  - JOUR
AU  - Johnson, R. H.
TI  - A new class of enumeration problems
JO  - Czechoslovak Mathematical Journal
PY  - 1974
SP  - 573
EP  - 583
VL  - 24
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1974.101276/
DO  - 10.21136/CMJ.1974.101276
LA  - en
ID  - 10_21136_CMJ_1974_101276
ER  -