@article {632,
	title = {The Palaeozoic seed Mitrospermum in American coal balls},
	journal = {Palaeontographica Abtheilung B},
	volume = {115},
	year = {1964},
	pages = {51-58},
	chapter = {51},
	author = {Taylor, Thomas N. and Stewart, Wilson Nichols}
}
@book {627,
	title = {Palaeobotany and the evolution of plants},
	year = {1993},
	pages = {521},
	publisher = {Cambridge university Press},
	organization = {Cambridge university Press},
	address = {Cambridge},
	url = {http://books.google.nl/books?id=Fhm-oed74JgC},
	author = {Stewart, Wilson Nichols and Rothwell, Gar W.}
}
