1. Capone, E., Niola, V., Bocchini, G.F., Capone, A., 1978. The four step porous bearing.Tribology International,12:330–336.
2. Chen, X., Li, Y.X., 2003. Porous metals: research advances and application.Materials,17(5):4–9 (in Chinese).
3. Cubo, J., Casinos, A., 1998. The variation of the cross-sectional geometry in the long bones of birds and mammals.annales des Sciences Naturelles,1:51–62.
4. Danielsson, M., Grenestedt, J.L., 1998. Gradient foam core materials for sandwich structures: preparation and characterization.Composites,29(A):981–988.
5. Davis, M.E., 2002. Ordered porous materials for emerging applications.Nature,417:813–822.