1. Circular Grid System — A Valuable Aid for Evaluating Sheet Metal Formability;Keeler;SAE Paper No. 680092,1968
2. Application of Strain Analysis to Sheet Metal Forming in the Press Shop;Goodwin;SAE Paper No. 680093,1968
3. Deformation analysis of large sized panels in the pressshop;Ishigaki,1978
4. Determination of Forming Limits in Automotive Stampings;Keeler;SAE Paper No. 650535,1965