TY  - RPRT
TI  - A mathematical model for use in evaluating and developing impact test methods for protective headgear 
AU  - Berger, Robert E
PY  - 1980
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS IR 80-1987
DO  - 10.6028/NBS.IR.80-1987
ER  -