1. J. C. Bronson, F. J. Edeskuty, J. H. Fretwell, E. F. Hammel, W. E. Keller, K. L. Meier, A. G. Schuch, and W. L. Willis, in Advances in Cryogenic Engineering, Vol. 7, Plenum Press, New York (1962), p. 198.
2. J. C. Burke, W. R. Byrnes, A. H. Post, and F. E. Ruccia, in Advances in Cryogenic Engineering, Vol. 4, Plenum Press, New York (1960), p. 378.
3. E. M. Drake, F. E. Ruccia, and J. M. Ruder, in Advances in Cryogenic Engineering, Vol. 6, Plenum Press, New York (1961), p. 323.
4. John Macinko, “Cooldown of Long Cryogenic Transfer Lines,” M.S. Thesis, University of Colorado (1960).
5. R. B. Jacobs, in Advances in Cryogenic Engineering, Vol. 8, Plenum Press, New York (1963), p. 529.