TY  - RPRT
TI  - Soil classification for construction practice in shallow trenching 
AU  - Yokel, Felix Y
AU  - Tucker, Richard L
AU  - Reese, Lymon C
PY  - 1979
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS IR 79-1945
DO  - 10.6028/NBS.IR.79-1945
ER  -