TY  - JOUR
AU  - E. Victor Flynn
AU  - Joseph L. Wetherell
TI  - Covering collections
and a challenge problem of Serre
JO  - Acta Arithmetica
PY  - 2001
SP  - 197
EP  - 205
VL  - 98
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/aa98-2-9/
DO  - 10.4064/aa98-2-9
LA  - en
ID  - 10_4064_aa98_2_9
ER  -