On the completeness of the Westergaard stress functions

H.M. Westergaard,Journal of Applied Mechanics, Transactions of the American Society of Mechanical Engineers (1939) A49?A53.

G.C. Sih,International Journal of Fracture Mechanics (1966) 628?630.

J. Eftis and H. Liebowitz,International Journal of Fracture Mechanics (1972) 383?392.

C.W. MacGregor,Transactions of the American Mathematical Society 38 (1935) 177?186.

N.I. Muskhelishvili,Some Basic Problems of the Mathematical Theory of Elasticity, Translated by J.R.M. Radok, 4th edn., Noordhoff, Leyden (1954).

R.V. Churchill, J.W. Brown and R.R. Verhey, inComplex Variables and Applications, 3rd edn., McGraw Hill, New York (1976) 136,40.

R.J. Sanford,Mechanics Research Communications 6 (1979) 289?294.

R. deWit, inFracture 1977, ICF4, Waterloo, Canada, D.M.R. Taplin (ed.), Pergamon Press, Vol 3 (1978) 185?189.