Barbour, M. (1983). The use of maps: the topographic and thematic traditions contrasted. The Cartographic Journal, 20(2), 76 - 86.

This study of the maps used to illustrate printed books on geographical topics shows that the number of such maps per book has substantially increased between A.D. 1500 and 1920, with a shift from simple outlines of land and sea, often borrowed from other sources, to more sophisticated representations of statistics and other distributions, often specially drawn. The printing of maps side by side to illustrate either temporal changes or similarities between distributions is shown to be an ancient practice, recently revived, while differences between authors in temperament and intellectual tradition also influence the maps they use to illustrate their books.