1. P. Andersson, Exact real computer arithmetic with automatic estimates in a computer algebra system, Department of Mathematics, Uppsala University, U.U.D.M. Report 2001:P5, 2001, .
2. H.-J. Boehm, R. Cartwright, M. Riggle, M. O’Donnell, Exact real arithmetic: a case study in higher order programming, in: ACM Symp. on Lisp and Functional Programming, 1986, pp. 162–173, .
3. A.J. Brentjes, Multi-dimensional continued fraction algorithms, Mathematical Centre Tracts, Vol. 145, Mathematisch Centrum Amsterdam, 1981, MR 83b:10038.
4. K.M. Briggs, XR homepage, , 2002.
5. K.M. Briggs, xrc homepage, , 2003.