1. Sintered alumina with low dielectric loss
2. Alford, N.McN., and Penn, S.J.: UK, (GB9815549.2)
3. Alford, N.McN., and Penn, S.J.: UK, (GB9815548)
4. Effect of Porosity and Grain Size on the Microwave Dielectric Properties of Sintered Alumina
5. Alford, N.McN., Penn, S.J., Templeton, A., Wang, X., and Webb, S.J.: ‘Effect of processing on the dielectric properties of ceramic dielectric resonator materials’, Alford, N.McN., Growth and processing of electronic materials, (Inst. Matls. 1998), p. 117–123