Facial action coding system page 130
Main Action Units
3 Oct AU 18+25+ AU 20+25+ AU AU AU AU AU AU AU 34 . AU AU AU AU AU AU 61/ AU 63/ Eyes around.  P. Ekman, W. V. Friesen, and J. C. Hager. Facial Action Coding System: The Manual . AU 50 = “Speech”. Combinations Muscles ≠ FACS.
Description:It is an anatomical system for describing all observable facial movement. It breaks down facial expressions into individual components of muscle movement. It was first published in by Ekman and Friesen, and has since undergone revision. The FACS manual is a comprehensive description of facial behavior.