L. M. Mann, “Notes (1) on Two Tribula or Threshing-Sledges, having their under surfaces studded with rows of chipped flints, for threshing corn on a threshing-floor, from Cavalla in European Turkey, now presented to the Museum; and (2) on Primitive Implements and Weap”, PSAS, vol. 38, pp. 506–519, Nov. 1904.