1. McDermott J, Shearer J, Tomczykowski W. “Resolution Cost Factors For Diminishing Manufacturing Sources And Material Shortages”. Defense MicroElectronics Activity (DMEA) Feb 1999.
2. The Ministry of Defence Directorate of Standardization. “Defense Standard 00-71 Iss. 2; Obsolescence Management”. Defence Procurement Agency. Jan 2001.
3. Raza K, Turner M “Cisco Network Topology and Design”. Cisco Press 2002.