Rudolph Modley, the most distinguished of the pupils of Otto Neurath, is better know for his large and comprehensive dictionaries/handbooks of symbols, e.g. Handbook of Pictorial Symbols. His own blend of the abstracted and the figurative is distinctive and should be better known. Much recommended is A History of the War in Maps, Pictographs, in words,(1943)and the didactic stidy, SYMBOLOGY, the use of Symbols in Graphic Communication of 1930 as well as USA in New Dimensions of 1957..
see also Public Opinion Quarterly, "Pictographs Today and Tomorrow" 1938; Pictographs and Graphs: How to Make and Use Them. Harper, New York 1952.
Modley founded the Pictograph Corporation in 1934 after working for the Chicago Museum of Science and Industry