Elena Barcucci Alberto Del Lungo Renzo Pinzani "Deco" Polyominoes, Permutations and Random Generation. 29-42 1996 159 Theor. Comput. Sci. 1 db/journals/tcs/tcs159.html#BarcucciLP96 http://dx.doi.org/10.1016/0304-3975(95)00199-9