8 May 2007. ^ Takhtajan, Armen, 1986. Floristic Regions of the World . (translated by T.J. Crovello & A. Cronquist). University of California Press , Berkeley . ^ Atlantic mixed forests (PA0402) , World Wildlife Fund, 2001. ^ Pearce, Fred (5 March 2003). “Sewage-laden Belgian water worst in world” . New