D. Fabiani, G. C. Montanari, C. Laurent, G. Teyssedre, P. H. F. Morshuis, R. Bodega,
L. A. Dissado, "HVDC cable design and space charge accumulation. Part 3: Effect of
temperature gradient", IEEE Electrical Insulation Magazine, Vol. 24, No. 2, pp. 5-14,
2008