by Chapman, J.N., Johnston, A.B., Heyderman, L.J., McVitie, S., Nicholson, W.A.P., Bormans, B.
Published in IEEE transactions on magnetics (01.11.1994)

by Bormans, B.J.M., Olbertz, A.H.M.
Published in Optics communications (01.09.1980)