An outline of European architecture / Nikolaus PevsnerHardmondsworth: Penguin, 1949 (Pelican Book)

“A new bird, the Pelican imprint series, emerged as an educational counterpart to the Penguin fiction titles (...) Tschichold began the design of the Pelicans by implementing a completely new look for the jackets and covers, thus, giving the series unique visual features to set them off from the current Penguin fiction series. Although he implemented a new identity for the Pelican book jackets and covers, the two design elements that carried over from the original book covers were the pale aqua blue color coding and the sans serif Gill Sans.”

Richard B. Doubleday. Jan Tschichold designer: the Penguin years. New Castle: Oak Knoll; Aldershot: Lund Humphries, 2006 (p. 53, 57 )