1. V. Alexeev: “Two two-dimensional terminations”, Duke Math. J., Vol. 69(3), (1993), pp. 527–545.
2. F. Ambro: “On minimal log discrepancies”, Math. Res. Lett., Vol. 6(5–6), (1999), pp. 573–580.
3. A. Borisov: “Minimal discrepancies of toric singularities”, Manuscripta Math., Vol. 92(1), (1997), pp. 33–45.
4. A. Borisov: “On classification of toric singularities”, Algebraic geom., Vol. 9; J. Math. Sci. (New York), Vol. 94(1), (1999), pp. 1111–1113.
5. Cambridge Tracts in Mathematics and Mathematical Physics;J.W.S. Cassels,1957