1. Joel, E. C. (2003). Human population: The next half century. Science, 302, 1172-1175 (2003)
2. Nancy, R. H., & Asuman, K. H. (2002) Social gerontology: A multidisciplinary perspective. 6th edn. Pearson.
3. Schlender, B. (2003). Intel Andy grove: The next battles in tech. Fortune, 80–81.
4. William, A. H. (2001). The last word: Health technology is coming home—And how! FDA Consumer, 35(1), 36.
5. Eric, D. (2004). Inventing wellness systems for aging in place. Computer, 37(5), 34–41.