1. Koiter, W. T.: Over de stabiliteit van het elastische evenwicht. Doctoral thesis, Delft, Holland, (1945),(NACA Tech. Trans. F 10, 833 (1967), and AFFDL-TR-70-25, 1970))
2. Augusti, G.: Stabilita' di structure elastiche elementari in presenza di grandi spostamenti, Atti Accad. Sci. fis. mat., Napoli, Serie 3a, 4, No. 5 (1964)
3. Thom, R.: Stabilité structurelle et morphogénèse. New York: Benjamin 1972
4. Thompson, J. M. T.; Hunt, G. W.: Towards a unified bifurcation theory. Z. Angew. Math. Phys. 26 (1975) 581?604
5. Sewell, M. J.: Some Mechanical Examples of Catastrophe Theory. Bull. Inst. Math. Appl. 12 (1976) 163?172