Observational evidence for superfluidity, and pinning, in the core of   neutron stars
  The observed large rates of spinning down after glitches in some radio pulsars has been previously explained in terms of a long-term spin-up behaviour of a superfluid part of the crust of neutron stars. We argue that the suggested mechanism is not viable; being inconsistent with the basic requirements for a superfluid spin-up, in addition to its quantitative disagreement with the data. One may therefore conclude, for the first time, that the presence and the pinned nature of neutron superfluid in the core of neutron stars is evidenced by the existing observational data. 
M. Jahan-Miri