A small aperiodic set of planar tiles
A set of tiles is called aperiodic if any tiling of the plane with congruent copies of the tiles is non-periodic. The author gives a set of two tiles that is proved to be aperiodic and new. The tiles occur in eight translation classes. The tiles are colored and a matching rule, that is, a local rule that restricts how the tiles are allowed to meet, is used (but the author gives a variant at the end of the paper that is purely geometrical).
scientific article; zbMATH DE number 1339811