Magnetic field of an in-plane vortex outside a layered superconductor
  We present the solution to London's equations for the magnetic fields of a vortex oriented parallel to the plane, and normal to a crystal face, of a layered superconductor. These expressions account for flux spreading at the superconducting surface, which can change the apparent size of the vortex along the planes by as much as 30%. We compare these expressions with experimental results. 
J.R. Kirtley, V.G. Kogan, J.R. Clem, and K.A. Moler