TY  - RPRT
TI  - Helium refrigeration and liquefaction using a liquid hydrogen refrigerator for precooling 
AU  - Chelton, Dudley B
PY  - 1960
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 39
DO  - 10.6028/NBS.TN.39
ER  -