1. American Society of Metals, ASTM metal handbook, vol. 4. 8th ed., 1964.
2. Proceedings of the North American Metalworking Research Conference, USA;Powell,1971
3. Proceedings of the 5th International Conference on Metal Forming 94, Birmingham, UK;Dohmann,1994
4. Fabrication of toroidal vessel section using elastomer mandrel;Bello,1988
5. Analysis of unconventional tee forming on metal tubes;Moreira Filho,1994