I.  Hoste, ?Ornamentals and invasive plants: if you choose one you get the other as well?, in Mini symposium on aliens and invasive species, National Botanic Garden of Belgium, Domein van Bouchout, B-1860 Meise, Belgium, 2013.

A.  Ronse, ?An Inventory of aliens escaping from culture in the National Botanic Garden of Belgium?, in Mini symposium on aliens and invasive species, National Botanic Garden of Belgium, Bouchout Castle, 2013.