(2) AUBERTIN, G. M., SMITH, D. W. & PATRIC, J. H.: Quantity and quality of streamflow after urea fertilization on a forested watershed-First year results. (For. Fer. Symp. Proc.) USDA For. Serv. Gen. Tech. Rep. NE-3: 88-100, 1973
(3) BORMANN, F. H. & LIKENS, G. E.: Nutrient cycling. Science 155: 424-429, 1967
(4) CRISP, D. T.: Input and output of minerals for on area of Pennine moorland-The importance of precipitation, drainage, peat erosion and animals. J. Appl. Ecol. 3: 327-348, 1966