Levelt, Willem J. M. Language Production Group Levelt, MPI for Psycholinguistics, Max Planck Society;
Levelt_1985_pointing.pdf (Publisher version), 3MB
Levelt, W. J. M., Richardson, G., & La Heij, W. (1985). Pointing and voicing in deictic expressions. Journal of Memory and Language, 24, 133-164. doi:10.1016/0749-596X(85)90021-X.