@article{GDZPPN002088959,
title = {Undecidability and Nonperiodicity for Tilings of the Plane.},
journal = {Inventiones mathematicae},
volume = {14},
year = {1971},
pages = {177-209},
zbl = {0197.46801},
url = {http://dml.mathdoc.fr/item/GDZPPN002088959}
}
Robinson, Raphael M. Undecidability and Nonperiodicity for Tilings of the Plane.. Inventiones mathematicae, Tome 14 (1971) pp. 177-209. http://gdmltest.u-ga.fr/item/GDZPPN002088959/