@inbook {7707,
	title = {Helianthus},
	booktitle = {Flora of North America},
	volume = {21},
	year = {2006},
	month = {2006///},
	pages = {141 - 169},
	publisher = {Oxford University Press},
	organization = {Oxford University Press},
	address = {New York-Oxford},
	author = {E.E. Schilling},
	editor = {Committee, Flora of North America Editorial}
}
@article {7081,
	title = {The origin of Helianthus x multiflorus and H. x laetiflorus (Asteraceae)},
	journal = {Biochem. Syst. Ecol},
	volume = {18},
	year = {1990},
	month = {1990///},
	pages = {19 - 23},
	author = {O. Spring and E.E. Schilling}
}
