1. Liu, J.Y.: Upper-bound solutions of some axisymmetric cold forging problems. ASME J. Eng. Ind. 93, 1134–1144 (1971)
2. Avitzur, B., Van Tyne, C.J.: Ring formation: an upper bound approach. Part 1: flow pattern and calculation of power. ASME J. Eng. Ind. 104, 231–237 (1982)
3. Avitzur, B., Van Tyne, C.J.: Ring formation: an upper bound approach. Part 2: process analysis and characteristics. ASME J. Eng. Ind. 104, 238–247 (1982)
4. Avitzur, B., Van Tyne, C.J.: Ring formation: an upper bound approach. Part 3: constrained forging and deep drawing applications. ASME J. Eng. Ind. 104, 248–252 (1982)
5. Avitzur, B., Sauerwine, F.: Limit analysis of hollow disk forging. Part 1: upper bound. ASME J. Eng. Ind. 100, 340–344 (1978)