1. Exploit the product life cycle;Levitt;Harvard Bus Rev.,1965
2. Patent term extension strategies in the pharmaceutical Industry;Bhat;Pharma Policy Law.,2005
3. Start early, sell more, sell longer;Daly;Pharma Exec.,2004
4. http://www.pulsetoday.co.uk/newsarticle-content/-/article_display_list/12478510/generic-gp -prescribing-drive-stalls 2012
5. www.worldcongress.com/events/nw515/pdf/VRExec Summ.pdf 2012