1. Baker, M.D., Reid, A.W.: Arithmetic knots in closed 3-manifolds. J. Knot Theory Ramif. 11(6), 903–920 (2002). Knots 2000 Korea, vol. 3 (Yongpyong)
2. Brunner A.M., Frame M.L., Lee Y.W. and Wielenberg N.J. (1984). Classifying torsion-free subgroups of the Picard group. Trans. Am. Math. Soc. 282(1): 205--235
3. Cannon, J.: Magma. University of Sydney, Sydney (2000)
4. Chinburg, T., Long, D., Reid, A.W.: Cusps of minimal non-compact arithmetic hyperbolic 3-orbifolds (submitted)(2006)
5. van der Geer, G.: Hilbert modular surfaces. In: Ergebnisse der Mathematik und ihrer Grenzgebiete (3) [Results in Mathematics and Related Areas (3)], vol. 16. Springer, Berlin Heidelberg New York (1988)