C K Wentworth, '' A scale of grade and class terms for clastic sediments '', J. Geology 30 : 377 -- 392 -LRB- 1922 -RRB-.
C K Wentworth, A scale of grade and class terms for clastic sediments, J. Geology V. 30, 377-392 -LRB- 1922 -RRB-.