@book{69081,
	author = {Beutelspacher, H  and Marel,  H W van der },
	title = {Atlas of electron microscopy of clay minerals and their admixtures = Atlas der Elektronenmikroskopie der Tonminerale und ihrer Beimengungen :},
	publisher = { Elsevier,},
	year = { 1968},
	address = {London :}
}