Hollis, Richard (2006). Swiss graphic design: the origins and growth of an international style, 1920-1965 (1st ed.). New Haven: Yale University Press. p. 124. ISBN0-300-10676-9. OCLC65221958."Although the first prize in the competition for a symbol . . . was won by Herman Eidenbenz, Warja Honegger-Lavater's design was selected for use. The four rings were intended to represent trade, light industry, heavy industry, and agriculture."
Hollis, Richard (2006). Swiss graphic design: the origins and growth of an international style, 1920-1965 (1st ed.). New Haven: Yale University Press. p. 114. ISBN0-300-10676-9. OCLC65221958.