@article {8184,
	title = {On the distribution of Ambrosia artemisiifolia L. (Asteraceae) in Bulgaria},
	journal = {Phytologia Balcanica},
	volume = {8},
	year = {2002},
	month = {2002///},
	pages = {31 - 33},
	author = {D.S. Dimitrov and R. Tzonev}
}
@article {8185,
	title = {Bidens frondosa (Asteraceae) - a new alien species for the Bulgarian flora},
	journal = {Phytologia Balcanica},
	volume = {10},
	year = {2004},
	month = {2004///},
	pages = {179 - 181},
	author = {K. Sumberova and R. Tzonev and V. Vladimirov}
}
