Consequences of a properly implemented computer arithmetic for periodicities of iterative methods. - Rudi Klatte; Christian P. Ullrich (IEEE Symposium on Computer Arithmetic, 1975)

Über die beim numerischen Rechnen mit komplexen Zahlen und Intervallen vorliegenden mathematischen Strukturen. - Christian P. Ullrich (Computing, 1975)

On conversions between screens. - Rudi Klatte; Christian P. Ullrich (Computing, 1980)

Complex sector arithmetic. - Rudi Klatte; Christian P. Ullrich (Computing, 1980)

FORTRAN for contemporary numerical computation. - Gerd Bohlender; Edgar Kaucher; Rudi Klatte; Ulrich W. Kulisch; Willard L. Miranker; Christian P. Ullrich; Jürgen Wolff von Gudenberg (Computing, 1981)

FORTRAN - Erweiterung für wissenschaftliches Rechnen. - Christian P. Ullrich (Wissenschaftliches Rechnen und Programmiersprachen, 1982)

A FORTRAN Extension for Scientific Computation. - Christian P. Ullrich (IMACS World Congress, 1982)

Rechnerarithmetik und die Weiterentwicklung von FORTRAN / Computer arithmetic and the development of FORTRAN. - Christian P. Ullrich (Elektron. Rechenanlagen, 1984)

Arithmetic Specification for Scientific Computation in ADA. - Rudi Klatte; Christian P. Ullrich; Jürgen Wolff von Gudenberg (IEEE Trans. Computers, 1985)

Numerical Stability of simple Geometric Algorithms in the plane. - Thomas Ottmann; Gerald Thiemt; Christian P. Ullrich (Computation Theory and Logic, 1987)

Numerical Stability of Geometric Algorithms. - Thomas Ottmann; Gerald Thiemt; Christian P. Ullrich (SCG, 1987)

FORTRAN-SC a study of a FORTRAN extension for engineering/scientific computation with access to ACRITH. - J. Hartmut Bleher; Siegfried M. Rump; Ulrich W. Kulisch; M. Metzger; Christian P. Ullrich; W. Walter (Computing, 1987)

New developments in Pascal-SC. - Gerd Bohlender; Christian P. Ullrich; Jürgen Wolff von Gudenberg (ACM SIGPLAN Notices, 1988)

Programming Languages for Enclosure Methods. - Christian P. Ullrich (Computer Arithmetic and Self-Validating Numerical Methods, 1990)

Pascal-XSC - Sprachbeschreibung mit Beispielen. - Rudi Klatte; Ulrich W. Kulisch; Michael Neaga; Dietmar Ratz; Christian P. Ullrich (Springer, 1991)

PASCAL-XSC: Language Reference with Examples - Ulrich W. Kulisch; Rudi Klatte; Dietmar Ratz; Michael Neaga; Christian P. Ullrich (PASCAL-XSC, 1992)

Coarse-grain parallelizations of interval algorithms decomposing dense matrices and solving triangular systems on multicomputers. - Roman Reith; Christian P. Ullrich (Computing, 1994)

A reliable linear algebra library for transputer networks. - Christian P. Ullrich; Roman Reith (Reliab. Comput., 1995)

Verified Solving of Linear Systems with Uncertainties in MAPLE. - Neli S. Dimitrova; Christian P. Ullrich (WNAA, 1996)

Componentwise Error Bounds and Direct Linear System Solving. - Beat Hörmann; Christian P. Ullrich (WNAA, 1996)

Embedding directed intervals in Mathematica. - Evgenija D. Popova; Christian P. Ullrich (RITA, 1996)

Software for fast validated solution of linear systems. - Christian P. Ullrich (RITA, 1996)

Verification May be Better than Estimation. - C. Falcó Korn; Beat Hörmann; Christian P. Ullrich (SIAM J. Sci. Comput., 1996)

Generalizing BIAS Specifications. - Evgenija D. Popova; Christian P. Ullrich (J. Univers. Comput. Sci., 1997)

Simplication of Symbolic-Numerical Interval Expressions. - Evgenija D. Popova; Christian P. Ullrich (ISSAC, 1998)

Solving Linear Systems with Error Control: Minisymposium within the 4th International Conference NMA'98. - Neli S. Dimitrova; Svetoslav Markov; Christian P. Ullrich (Reliab. Comput., 1999)