Operator bias characterizing stream substrates using Wolman pebble counts with a standard measurement template
https://stroudcenter.org/wp-content/uploads/2016/09/Lofty-Stream-Dave-Funk-1024x681.jpg 1024 681 Stroud Water Research Center Stroud Water Research Center https://stroudcenter.org/wp-content/uploads/2016/09/Lofty-Stream-Dave-Funk-1024x681.jpgDaniels, M.D., and M.H. McCusker. 2010. Geomorphology 115:194–198.