Early work on facial motion synthesis, facial motion recognition, and a psychological approach to facial coding:
Yuencheng Lee, Demetri Terzopoulos, and Keith Waters. (1995). Realistic Modeling for Facial Animation. Proc. ACM SIGGRAPH, 55-62.
Irfan A. Essa and Alex P. Pentland. (1997). Coding, Analysis, Interpretation, and Recognition of Facial Expressions. IEEE PAMI, 19, 7, 757-763.
