Dobner, Hans-Jürgen. “Computing Reliable Error Estimations for Integral Equations With Discontinuities”.
Rev. Anal. Numér. Théor. Approx.
, vol. 27, no. 2, Aug. 1998, pp. 227-36,
https://ictp.acad.ro/jnaat/journal/article/view/1998-vol27-no2-art4
.