1. Existence and regularity almost everywhere of solutions to elliptic variational problems with constraints;Almgren, F. J., Jr.;Mem. Amer. Math. Soc.,1976
2. [AKS] Fred Almgren, Rob Kusner, and John M. Sullivan, A comparison of the Kelvin and Weaire-Phelan foams, in preparation.
3. Problem Books in Mathematics;Croft, Hallard T.,1991
4. An isoperimetric problem for tessellations;Fejes Tóth, G.;Studia Sci. Math. Hungar.,1975
5. Maximal orders in rational cyclic algebras of composite degree;Perlis, Sam;Trans. Amer. Math. Soc.,1939