@INCOLLECTION{beuls:12b, author = {Beuls, Katrien and Steels, Luc and H"{o}fer, Sebastian},title = {The Emergence of Internal Agreement Systems},year = {2012},booktitle = {Experiments in Cultural Language Evolution},pages = {233--256},publisher = {John Benjamins},editor = {Steels, Luc},address = {},}