Geodesic
Fisher's inequality for tactical configurations
Matematičeskie zametki, Tome 4 (1968) no. 4, pp. 417-424 
A. Ya. Petrenyuk. Fisher's inequality for tactical configurations. Matematičeskie zametki, Tome 4 (1968) no. 4, pp. 417-424. http://geodesic.mathdoc.fr/item/MZM_1968_4_4_a4/
@article{MZM_1968_4_4_a4,
     author = {A. Ya. Petrenyuk},
     title = {Fisher's inequality for tactical configurations},
     journal = {Matemati\v{c}eskie zametki},
     pages = {417--424},
     year = {1968},
     volume = {4},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1968_4_4_a4/}
}
TY  - JOUR
AU  - A. Ya. Petrenyuk
TI  - Fisher's inequality for tactical configurations
JO  - Matematičeskie zametki
PY  - 1968
SP  - 417
EP  - 424
VL  - 4
IS  - 4
UR  - http://geodesic.mathdoc.fr/item/MZM_1968_4_4_a4/
LA  - ru
ID  - MZM_1968_4_4_a4
ER  - 
%0 Journal Article
%A A. Ya. Petrenyuk
%T Fisher's inequality for tactical configurations
%J Matematičeskie zametki
%D 1968
%P 417-424
%V 4
%N 4
%U http://geodesic.mathdoc.fr/item/MZM_1968_4_4_a4/
%G ru
%F MZM_1968_4_4_a4

Voir la notice de l'article provenant de la source Math-Net.Ru

It is proved that for $l\geqslant4$ the number $b$ of blocks of a tactical configuration $C(k,l,\lambda,v)$ is at least equal to $\tbinom{v}{2}$.