@book {554,
	title = {Euthecosomata, a group with remarkable developmental stages (Gastropoda, Pteropoda)},
	year = {1967},
	pages = {375},
	publisher = {J. Noorduyn \& ZN, Gorinchem},
	organization = {J. Noorduyn \& ZN, Gorinchem},
	author = {S. Van Der Spoel}
}
