6Weaire D, Phelan R. A counter-example to Kevin's conjecture on minimal surfaces [J]. Philosophical Magazine Letters, 1994, 69(2): 107-110.
7Weaire D, Hutzler S. The Physics of Foams [M]. Oxford: Clarendon, 1999.
8Cox S J, Graner F, et al. Minimal perimeter for N identical bubbles in two dimensions: calculations and simulation [J]. Philosophical Magazine, 2003, 83(11): 1393-1406.
9Rob K, John M S. Comparing the Weaire-Phelan equal-volume foam to Kelvin's foam [J]. Forma, 1996, 11(3): 233-242.