1. Nadai, A., Theory of Flow and Fracture of Solids, 2nd Ed., Vol.1, pp.347-352, McGraw-Hill Book Co., Inc., New York, 1950.
2. Shanley, F. R., Strength of Materials, pp.183-190, McGraw-Hill Book Co., Inc., New York, 1957.
3. Bending Strength in the Plastic Range