TY - GEN AU - Chelton, Dudley B C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1960-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.TN.39 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1960 TI - Helium refrigeration and liquefaction using a liquid hydrogen refrigerator for precooling: ER -