@article {8472,
	title = {{\"U}bersicht {\"u}ber die in Kultur befindlichen Cotoneaster-Arten},
	journal = {Wiss. Z. Univ. Halle, Math.-Nat},
	volume = {6},
	year = {1957},
	month = {1957///},
	pages = {945 - 982},
	author = {G. Klotz}
}
@article {8397,
	title = {Aubrieta deltoidea (l.) DC. Correspondentiebl. Florist},
	journal = {Veg.-Onderz. Ned},
	volume = {3},
	year = {1957},
	month = {1957///},
	pages = {27 - 28},
	author = {S.E. De Jongh}
}
@article {8249,
	title = {Synopsis of Rudbeckia subgenus Rudbeckia},
	journal = {Rhodora},
	volume = {59},
	year = {1957},
	month = {1957///},
	pages = {293 - 299},
	author = {R.E. Perdue}
}
@article {8163,
	title = {Taxonomy of the genus Heliopsis (Compositae)},
	journal = {Ohio J. Sc},
	volume = {57},
	year = {1957},
	month = {1957///},
	pages = {171 - 191},
	author = {T.R. Fischer}
}
@article {7904,
	title = {{\"U}ber Verwechslungen von Phytolacca acinosa mit Phytolacca americana},
	journal = {Hess. Florist. Briefe},
	volume = {6},
	year = {1957},
	month = {1957///},
	pages = {281 - 282},
	author = {W. Ludwig}
}
@article {7345,
	title = {Enige voor Belgi{\"e} nieuwe adventieve Medicago-soorten},
	journal = {Bull. Jard. Bot. Etat Brux},
	volume = {27},
	year = {1957},
	month = {1957///},
	pages = {669 - 674},
	author = {S.J. Van Ooststroom and Th.J. Reichgelt}
}
@article {7181,
	title = {Bidens vulgata Greene},
	journal = {Bot. Soc. Brit. Isles Proc},
	volume = {2},
	year = {1957},
	month = {1957///},
	author = {D.P. Young}
}
@article {7118,
	title = {Contribution {\`a} l_{\'e}tude de la flore adventice de la Belgique. I. Adventices rares ou nouvelles pour la Belgique. Bull. Soc. Roy},
	journal = {Bot. Belg},
	volume = {89},
	year = {1957},
	month = {1957///},
	pages = {85 - 100},
	author = {J. Lambinon}
}
