Blanck, J., & Blanck, J. (2006). Exact real arithmetic using centred intervals and bounded error terms. The Journal of Logic and Algebraic Programming, 66(1), p. 50. doi:10.1016/j.jlap.2005.07.002

Blanck, Jens, and J. Blanck. "Exact Real Arithmetic Using Centred Intervals and Bounded Error Terms." The Journal of Logic and Algebraic Programming 66, no. 1 (2006): 50.

Blanck, Jens, and J. Blanck. "Exact Real Arithmetic Using Centred Intervals and Bounded Error Terms." The Journal of Logic and Algebraic Programming 66.1 (2006): 50.