erc: who: Harper, John Howard what: Density Profile of a Quantized Vortex Line in Superfluid Helium-4 when: 19750500 where: https://digital.library.unt.edu/ark:/67531/metadc500722/ erc-support: who: University of North Texas Libraries what: Permanent: Stable Content: when: 20081203 where: https://digital.library.unt.edu/ark:/67531/