@article{GDZPPN002292173, title = {Tag Systems and Lag Systems.}, journal = {Mathematische Annalen}, volume = {152}, year = {1963}, pages = {65-74}, zbl = {0131.24602}, url = {http://dml.mathdoc.fr/item/GDZPPN002292173} }
Wang, H. Tag Systems and Lag Systems.. Mathematische Annalen, Tome 152 (1963) pp. 65-74. http://gdmltest.u-ga.fr/item/GDZPPN002292173/