Jonathan P. is a researcher that has a website called MissionaryHelp.com which has a section on research you might be interested in. He has done people group research in Africa and works in missionary logistics currently. Visit the website, you will find many links and articles there such as What is a People Group?, Ethnographic Interview, Gobalization and Christianity, People Group and Country Research on the Web, People Groups on Google Earth, Harvest Information System etc. He has even promoted Etnopedia. Thanks Jonathan!