This is a partial list of the references that I used or found about this approach and related ideas. I intend to add more references as I find them in the future.
Atick, Joseph J, Paul A. Griffin, and A. Norman Redlich. "Face Recognition from Live Video for Real-World Applications--Now." Advanced Imaging May 1995: 58-60.
Benson, P. J., and D. I. Perrett "Extracting prototypical facial images from exemplars." Perception 22 (1993): 257-262.
Burt, D. Michael, and David I. Perrett, "Perception of age in adult Caucasian male faces: computer graphic manipulation of shape and colour information." Proc. R. Soc. London, 259 (1995): 137-143.
Dewdney, A. K., The Tinkertoy Computer. New York: Viking, 1995.
Galton, F. J. "Composite portraits." Nature, Lond. 18 (1878): 97-100.
Green, Bill. "Edgewarp code." Personal e-mail (17 April 1996).
Golub, G. H. and C. F. Loan. Matrix Computations. Baltimore: John Hopkins University Press, 1983.
Lee, Kieran, Dave Perrett, Duncan Rowland, and Mike Burt. "Facial Prototyping." http://psych.st-and.ac.uk:8080/research/perception_lab/prototyping/ (30 April 1996).
Perrett, D. I., K. A. May, and S. Yoshikawa. "Facial shape and judgements of female attractiveness." Nature 368 (17 March 1994): 239-242.
Rowland, Duncan A. "Pulling Faces" SIGGRAPH Technical Sketch Lecture. 9 August 1995.
Ruprecht, Detlef, and Heinrich Muller. "Image Warping with Scattered Data Interpolation Methods." Technical Report, Universitat Dortmund. 6 November 1992.