Link to Google Scholar
Here
is my hard to find 2000 paper``Asymptotic formulas for
perturbations in the
electromagnetic
fields due to the presence of inhomogeneities of small
diameter'', M. Vogelius and D. Volkov,
Mathematical Modelling and Numerical Analysis, M2AN, Vol. 34,
N 4, 2000, pp. 723-748.