The Meaning of Sangha - Essay on the thesis that the monastic order is the true "sangha" of Buddhism. - http://www.buddhistinformation.com/meaning_of_sangha.htm
Sangha Means Community - Dharma talk by on the role of friends and community in the spiritual life. - http://www.dzogchen.org/teachings/talks/dtalk-94dec12.html
Sangha: The Ideal World Community - An analysis of the different types of sangha, and their relationship to the world community. - http://www.saigon.com/~anson/ebud/ebdha062.htm
The Dharma Tree - A primer of the role of sangha in the Buddhist life. - http://www.saigon.com/~anson/ebud/ebdha034.htm