TY - GEN AU - McConnell, Philip M C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1973-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.IR.73-316 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1973 TI - Liquid helium pumps: ER -