An early description of the procedure of having single digits called out, which the performer arranges in descending order to create a free page selection, thus subtly limiting the number of possible pages that can be selected, seems to be in H. G. Cleveland's “Dictionary Test” on p. 59 of The Linking Ring, Vol. 33, No. 8, October 1953. However, since this ranging force was included in Boardé's 1950 Mainly Mental, Volume Two, there has to be an earlier source.