1. D. Broek, ?Elementary Engineering Fracture Mechanics?, 3rd Edn (Nijhoff, Dordrecht, 1984).
2. J. F. Knott, ?Fundamentals of Fracture Mechanics? (Butterworths, London, 1973).
3. T. Uesaka, in ?Handbook of Physical and Mechanical Testing of Paper and Paperboard?, Vol. 1, edited by R. E. Mark (Dekker, New York, 1983) p. 77.
4. R. Steadman and C. Fellers, paper presented at International Paper Physics Seminar, Minnowbrook, New York, August 1986.
5. Idem, paper presented at International Paper Physics Conference, Mont-Rolland, Canada, September 1987.