Reference citation: E. Percival and H. Whitehead (1929). A Quantitative Study of the Fauna of Some Types of Stream-Bed. Journal of Ecology. 17(2), pp. 282-314.
Reference citation: E. Percival and H. Whitehead, 1929. A quantitative study of the fauna of some types of stream-bed. J. Ecol. 17:282-314, from p. 311 & overleaf.