with Shiing-Shen Chern and Phillip Griffiths, Exterior differential systems,
in Proceedings of the 1980 Beijing Symposium on Differential Geometry and Differential Equations (Beijing, 1980), edited by S. S. Chern and Wen Tsün Wu, vol. 1
(1982),
pp. 219–338, Science Press, Beijing
(last updated on 2004/07/24)
Author's Comments:
This is a brief introduction to the ideas of exterior
differential systems. It was later expanded and became
the basis of our 1991 book with
Gardner and Goldschmidt of the same title.