Key BD, Howell RD, Criddle CS.
Fluorinated organics in the biosphere. Environmental Science and Technology. 1997 ;31:2445-2454.
Fowler D, Cape JN, Unsworth MH.
Deposition of atmospheric pollutants on forests. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences. 1989 ;324:247-265.