@Article{a-cccaf-88,
author = { Helmut Alt },
title = { Comparing the combinational complexities of arithmetic functions },
journal = { J. ACM },
year = { 1988 },
volume = { 35 },
pages = { 447-460 },
}
@Article{mna-lbcus-88,
author = { Helmut Alt and Kurt Mehlhorn and Stefan N{\"a}her },
title = { A lower bound on the complexity of the union-split-find problem },
journal = { SIAM J. Comput. },
year = { 1988 },
volume = { 17 },
pages = { 1093-1102 },
}
@Article{amww-cssgo-88,
author = { },
title = { Congruence, similarity and symmetries of geometric objects },
journal = { Discrete Comput. Geom. },
year = { 1988 },
volume = { 3 },
}
@Article{aw-vgoas-88,
author = { Helmut Alt and Emo Welzl },
title = { Visibility graphs and obstacle-avoiding shortest paths },
journal = { Zeitschrift f{\"u}r Operations Research },
year = { 1988 },
volume = { 32 },
number = { 145-164 },
}
