@booklet {6999,
	title = {VAIL, J.R. 1985. Alkaline ring complexes in Sudan. Journal of African Earth Sciences, 3: 51-9.},
	year = {1985},
	note = {VAIL, J.R. 1985. Alkaline ring complexes in Sudan. Journal of African Earth Sciences, 3: 51-9.}
}
