@article {7878,
	title = {Medicago sativa in Mitteleuropa angebaut und verwildert?},
	journal = {G{\"o}tt. Florist. Rundbr.},
	volume = {7},
	year = {1973},
	month = {1973///},
	pages = {9 - 13},
	author = {H. Vollrath}
}
@article {7171,
	title = {Drawings of Scandinavian plants: 86-88. Chenopodium L},
	journal = {Bot. Notiser},
	volume = {126},
	year = {1973},
	month = {1973///},
	pages = {135 - 141},
	author = {L. Engstrand and M. Gustafsson}
}
@article {6901,
	title = {Natural hybridization in Ipomoea (Convolvulaceae)},
	journal = {Amer. J. Bot.},
	volume = {60},
	year = {1973},
	month = {1973///},
	pages = {33 - 34},
	author = {Abel, W.E. and Austin, D.F.}
}
