Bica, Alexandru. “The Error Estimation in Terms of the First Derivative in a Numerical Method for the Solution of a Delay Integral Equation from Biomathematics”. Rev. Anal. Numér. Théor. Approx., vol. 34, no. 1, Feb. 2005, pp. 23-36, https://doi.org/10.33993/jnaat341-788.