@book{550755,
	author = {Boissevain Jeremy and  Mitchell J Clyde Ed.},
	title = {Network analysis },
	publisher = {Mouton          },
	year = {1973},
	series = {Change and Continuity in Africa. Ed by J F Holleman atc},
	address = {Hague},
	note = {Bibliography P 251-55}
}