1. G. Alefeld, J. Herzberger, Introduction to Interval Computations, Academic Press, New York, 1983.
2. G. Birkhoff, Lattice Theory, AMS Colloquium Public., 25, New York, 1940.
3. N. Dimitrova, S. Markov, On the Interval-arithmetic Presentation of the Range of a Class of Monotone Functions of Many Variables. In: Computer Arithmetic, Scientific Computation and Mathematical Modelling, E. Kaucher, S. Markov, G. Mayer (Eds.), J. C. Baltzer Publ., IMACS, 12, 1991, 213–228.
4. N. Dimitrova, S. Markov, E. Popova, Extended interval arithmetics: new results and applications. In: Computer arithmetic and enclosure methods (Eds. L. Atanassova, J. Herzberger) North-Holland, Amsterdam, 1992, 225–232.
5. N. Dimitrova, S. Markov, A Validated Newton Type Method for Nonlinear Equations, Interval Computation, 1994, 2, 27–51.