A language over a one symbol alphabet requiring only O (log log n) space. - Helmut Alt; Kurt Mehlhorn (SIGACT News, 1975)

Lower Bounds for the Space Complexity of Context-Free Recognition. - Helmut Alt; Kurt Mehlhorn (ICALP, 1976)

Eine untere Schranke für den Platzbedarf bei der Analyse beschränkter kontextfreier Sprachen. - Helmut Alt (1976)

Eine untere Schranke für den Platzbedarf bei der Analyse beschränkter kontextfreier Sprachen. - Helmut Alt (Theoretical Computer Science, 1977)

The complexity of complex division (extended abstract). - Helmut Alt; Jan van Leeuwen (FCT, 1979)

Lower Bounds on Space Complexity for Contextfree Recognition. - Helmut Alt (Acta Informatica, 1979)

Square rooting is as difficult as multiplication. - Helmut Alt (Computing, 1979)

Complexity arguments in algebraic language theory. - Helmut Alt; Kurt Mehlhorn (RAIRO Theor. Informatics Appl., 1979)

Functions Equivalent to Integer Multiplication. - Helmut Alt (ICALP, 1980)

The complexity of basic complex operations. - Helmut Alt; Jan van Leeuwen (Computing, 1981)

Comparison of Arithmetic Functions with Respect to Boolean Circuit Depth (Extended Abstract) - Helmut Alt (STOC, 1984)

Partial Match Retrieval in Implicit Data Structures. - Helmut Alt; Kurt Mehlhorn; J. Ian Munro (Inf. Process. Lett., 1984)

Searching Semisorted Tables. - Helmut Alt; Kurt Mehlhorn (SIAM J. Comput., 1985)

Multiplication is the Easiest Nontrivial Arithmetic Function. - Helmut Alt (Theor. Comput. Sci., 1985)

Deterministic Simulation of Idealized Parallel Computers on More Realistic Ones. - Helmut Alt; Torben Hagerup; Kurt Mehlhorn; Franco P. Preparata (SIAM J. Comput., 1987)

Congruence, Similarity, and Symmetries of Geometric Objects. - Helmut Alt; Kurt Mehlhorn; Hubert Wagener; Emo Welzl (Discret. Comput. Geom., 1988)

Approximation of Polygons by Rechtangles and Circles. - Helmut Alt; Hubert Wagener (Bull. EATCS, 1988)

Comparing the combinational complexities of arithmetic functions. - Helmut Alt (J. ACM, 1988)

Visibility graphs and obstacle-avoiding shortest paths. - Helmut Alt; Emo Welzl (ZOR Methods Model. Oper. Res., 1988)

A Lower Bound on the Complexity of the Union-Split-Find Problem. - Kurt Mehlhorn; Stefan Näher; Helmut Alt (SIAM J. Comput., 1988)

Motion Planning in the CL-Environment (Extended Abstract). - Chee-Keng Yap; Helmut Alt (WADS, 1989)

Approximation of Convex Polygons. - Helmut Alt; Johannes Blömer; Hubert Wagener (ICALP, 1990)

Approximate Matching of Polygonal Shapes (Extended Abstract). - Helmut Alt; Bernd Behrends; Johannes Blömer (SCG, 1991)

Computing a Maximum Cardinality Matching in a Bipartite Graph in Time O(^1.5 sqrt m/log n). - Helmut Alt; Norbert Blum; Kurt Mehlhorn; Markus Paul (Inf. Process. Lett., 1991)

Measuring the Resemblance of Polygonal Curves. - Helmut Alt; Michael Godau (SCG, 1992)

Resemblance and Symmetries of Geometric Patterns. - Helmut Alt; Johannes Blömer (Data Structures and Efficient Algorithms, 1992)

Approximate Motion Planning and the Complexity of the Boundary of the Union of Simple Geometric Figures. - Helmut Alt; Rudolf Fleischer; Michael Kaufmann 001; Kurt Mehlhorn; Stefan Näher; Stefan Schirra; Christian Uhrig (Algorithmica, 1992)

A Lower Bound for the Nondeterministic Space Complexity of Context-Free Recognition. - Helmut Alt; Viliam Geffert; Kurt Mehlhorn (Inf. Process. Lett., 1992)

An Application of Point Pattern Matching in Astronautics. - Gerald Weber; Lars Knipping; Helmut Alt (J. Symb. Comput., 1994)

Computing the largest inscribed isothetic rectangle. - Helmut Alt; David Hsu; Jack Snoeyink (CCCG, 1995)

The Voronoi Diagram of Curved Objects. - Helmut Alt; Otfried Schwarzkopf (SCG, 1995)

Approximate Matching of Polygonal Shapes. - Helmut Alt; Bernd Behrends; Johannes Blömer (Ann. Math. Artif. Intell., 1995)

Computing the Fréchet distance between two polygonal curves. - Helmut Alt; Michael Godau (Int. J. Comput. Geom. Appl., 1995)

A Method for Obtaining Randomized Algorithms with Small Tail Probabilities. - Helmut Alt; Leonidas J. Guibas; Kurt Mehlhorn; Richard M. Karp; Avi Wigderson (Algorithmica, 1996)

Piecewise Linear Approximation of Bézier-Curves. - Helmut Alt; Emo Welzl; Barbara Wolfers (SCG, 1997)

Matching Shapes with a Reference Point. - Oswin Aichholzer; Helmut Alt; Günter Rote (Int. J. Comput. Geom. Appl., 1997)

Point-Sets with few k-Sets. - Helmut Alt; Stefan Felsner; Ferran Hurtado; Marc Noy (SCG, 1998)

Matching Convex Shapes with Respect to the Symmetric Difference. - Helmut Alt; Ulrich Fuchs 001; Günter Rote; Gerald Weber (Algorithmica, 1998)

Universal 3-dimensional visibility representations for graphs. - Helmut Alt; Michael Godau; Sue Whitesides (Comput. Geom., 1998)

On The Number Of Simple Cycles In Planar Graphs. - Helmut Alt; Ulrich Fuchs 001; Klaus Kriegel (Comb. Probab. Comput., 1999)

Discrete Geometric Shapes: Matching, Interpolation, and Approximation. - Helmut Alt; Leonidas J. Guibas (Handbook of Computational Geometry, 2000)

Packing Convex Polygons into Rectangular Boxes. - Helmut Alt; Ferran Hurtado (JCDCG, 2000)

A class of point-sets with few k-sets. - Helmut Alt; Stefan Felsner; Ferran Hurtado; Marc Noy; Emo Welzl (Comput. Geom., 2000)

The Nearest Neighbor. - Helmut Alt (Computational Discrete Mathematics, 2001)

Exact Linfty Nearest Neighbor Search in High Dimensions. - Helmut Alt; Laura Heinrich-Litan (SCG, 2001)

Matching Polygonal Curves with Respect to the Fréchet Distance. - Helmut Alt; Christian Knauer; Carola Wenk (STACS, 2001)

On the worst-case complexity of the silhouette of a polytope. - Helmut Alt; Marc Glisse; Xavier Goaoc (CCCG, 2003)

The complexity of (un)folding. - Helmut Alt; Christian Knauer; Günter Rote; Sue Whitesides (SCG, 2003)

Finding a curve in a map. - Carola Wenk; Helmut Alt; Alon Efrat; Lingeshwaran Palaniappan; Günter Rote (SCG, 2003)

Matching planar maps. - Helmut Alt; Alon Efrat; Günter Rote; Carola Wenk (J. Algorithms, 2003)

Comparison of Distance Measures for Planar Curves. - Helmut Alt; Christian Knauer; Carola Wenk (Algorithmica, 2004)

Semi-computability of the Fréchet distance between surfaces. - Helmut Alt; Maike Buchin (EuroCG, 2005)

The Voronoi Diagram of Curved Objects. - Helmut Alt; Otfried Cheong; Antoine Vigneron (Discret. Comput. Geom., 2005)

Foreword. - Helmut Alt (Theory Comput. Syst., 2005)

Minimum-cost coverage of point sets by disks. - Helmut Alt; Esther M. Arkin; Hervé Brönnimann; Jeff Erickson 001; Sándor P. Fekete; Christian Knauer; Jonathan Lenchner; Joseph S. B. Mitchell; Kim Whittlesey (SCG, 2006)

Probabilistic matching and resemblance evaluation of shapes in trademark images. - Helmut Alt; Ludmila Scharf; Sven Scholz (CIVR, 2007)

Computing the Hausdorff Distance between Curved Objects. - Helmut Alt; Ludmila Scharf (Int. J. Comput. Geom. Appl., 2008)

Schnelle Sortieralgorithmen. - Helmut Alt (Taschenbuch der Algorithmen, 2008)

The Computational Geometry of Comparing Shapes. - Helmut Alt (Efficient Algorithms, 2009)

09111 Abstracts Collection - Computational Geometry. - Pankaj Kumar Agarwal; Helmut Alt; Monique Teillaud (Computational Geometry, 2009)

Constructing Optimal Highways. - Hee-Kap Ahn; Helmut Alt; Tetsuo Asano; Sang Won Bae 001; Peter Brass; Otfried Cheong; Christian Knauer; Hyeon-Suk Na; Chan-Su Shin; Alexander Wolff 001 (Int. J. Found. Comput. Sci., 2009)

Wooden Geometric Puzzles: Design and Hardness Proofs. - Helmut Alt; Hans L. Bodlaender; Marc J. van Kreveld; Günter Rote; Gerard Tel (Theory Comput. Syst., 2009)

Probabilistic matching of planar regions. - Helmut Alt; Ludmila Scharf; Daria Schymura (Comput. Geom., 2010)

Can We Compute the Similarity between Surfaces? - Helmut Alt; Maike Buchin (Discret. Comput. Geom., 2010)

Fast Sorting Algorithms. - Helmut Alt (Algorithms Unplugged, 2011)

Minimum cell connection and separation in line segment arrangements - Helmut Alt; Sergio Cabello; Panos Giannopoulos; Christian Knauer (CoRR, 2011)

Computation of the Hausdorff distance between sets of line segments in parallel - Helmut Alt; Ludmila Scharf (CoRR, 2012)

Shape matching by random sampling. - Helmut Alt; Ludmila Scharf (Theor. Comput. Sci., 2012)

Scandinavian Thins on Top of Cake: New and Improved Algorithms for Stacking and Packing. - Helmut Alt; Esther M. Arkin; Alon Efrat; George Hart; Ferran Hurtado; Irina Kostitsyna; Alexander Kröller; Joseph S. B. Mitchell; Valentin Polishchuk (Theory Comput. Syst., 2014)

A Middle Curve Based on Discrete Fréchet Distance. - Hee-Kap Ahn; Helmut Alt; Maike Buchin; Eunjin Oh 001; Ludmila Scharf; Carola Wenk (LATIN, 2016)

Thoughts on Barnette's Conjecture. - Helmut Alt; Michael S. Payne; Jens M. Schmidt; David R. Wood (Australas. J Comb., 2016)

Bundling three convex polygons to minimize area or perimeter. - Dongwoo Park; Sang Won Bae 001; Helmut Alt; Hee-Kap Ahn (Comput. Geom., 2016)

Computational Aspects of Packing Problems. - Helmut Alt (Bull. EATCS, 2016)

Minimum Cell Connection in Line Segment Arrangements. - Helmut Alt; Sergio Cabello; Panos Giannopoulos; Christian Knauer (Int. J. Comput. Geom. Appl., 2017)

Approximating Minimum-Area Rectangular and Convex Containers for Packing Convex Polygons. - Helmut Alt; Mark de Berg; Christian Knauer (J. Comput. Geom., 2017)

Approximating Smallest Containers for Packing Three-Dimensional Convex Objects. - Helmut Alt; Nadja Scharf (Int. J. Comput. Geom. Appl., 2018)

Placing your coins on a shelf. - Helmut Alt; Kevin Buchin; Steven Chaplick; Otfried Cheong; Philipp Kindermann; Christian Knauer; Fabian Stehn (J. Comput. Geom., 2018)

Packing 2D Disks into a 3D Container. - Helmut Alt; Otfried Cheong; Ji-won Park; Nadja Scharf (WALCOM, 2019)

Middle curves based on discrete Fréchet distance. - Hee-Kap Ahn; Helmut Alt; Maike Buchin; Eunjin Oh 001; Ludmila Scharf; Carola Wenk (Comput. Geom., 2020)