5Burkhardt T H, Stout B A. Laboratory investigations of corn shelling utilizing high velocity impact loading[J]. Transactions of the ASAE, 1974, 17(3) :11 -- 14.
6Mahmoud Ali R, Buchele W F. Corn ear orientation effects on mechanical damage and forces on concave[J]. Transactions of the ASAE, 1975, 18(3):444-447.