TY  - RPRT
TI  - Instability in a sand heap.
AU  - P Evesque
AU  - J Rajchenbach
PY  - 1989
DO  - 10.1103/physrevlett.62.44
UR  - https://pubmed.ncbi.nlm.nih.gov/10039544/
ID  - 10039544
ER  -