TY - JOUR T1 - Bidens frondosa (Asteraceae) - a new alien species for the Bulgarian flora JF - Phytologia Balcanica Y1 - 2004 A1 - K. Sumberova A1 - R. Tzonev A1 - V. Vladimirov SP - 179 EP - 181 VL - 10 ER - TY - JOUR T1 - Two alien species of Bidens (Asteraceae) new to the Bulgarian flora. Phytol JF - Balcan Y1 - 2009 A1 - A.S. Petrova A1 - V. Vladimirov SP - 367 EP - 371 VL - 15 IS - 3 ER - TY - JOUR T1 - Erigeron sumatrensis (Asterace ae): a recently recognized alien species in the Bulgarian flora. Phytol JF - Balcan Y1 - 2009 A1 - V. Vladimirov SP - 361 EP - 365 VL - 15 IS - 3 ER -