 Where multiple copies of the polyominoes in the set are allowed, Golomb defines a hierarchy of different regions that a set may be able to tile, such as rectangles, strips, and the whole plane, and shows that whether polyominoes from a given set can tile the plane is undecidable, by mapping sets of Wang tiles to sets of polyominoes.Another class of problems asks whether copies of a given polyomino can tile a rectangle, and if so, what rectangles they can tile.These problems have been extensively studied for particular polyominoes, and tables of results for individual polyominoes are available.