1. 1) L. J. Gibson and M. F. Ashby: Cellular Solids, (2nd edition, Cambridge Univ. Press, 1997) pp. 1–14.
2. 2) M. F. Ashby, A. Evans, N. A. Fleck, L. J. Gibson, J. W. Hutchinson and H. N. G. Wadley: Metal Foams, (Butterworth-Heinemann Ltd, 2000) pp. 6–23.
3. 3) L. V. Boiko, V. I. Shapovalov and E. A. Chernykh: Metallurgiya 346 (1991) 78–81.
4. 4) H. Nakajima: Materials Integration 12 (1999) 37–44.
5. 5) H. Nakajima: The Production & Technique 51 (1999) 60–62.