1. Vgl. F. Kiefer, Mathematical linguistics in Eastern Europe. New York 1968. S. 3–5.
2. Z. B. V. Krupa, The phonemic structure of bivocalic morphemic forms in Oceanic languages. Journal of the Polynesian Society 75, 1966,458–497.
3. Vgl. z. B. J. E. Grimes, F. B. Agard, Linguistic divergence in Romance. Language 35,1959, 598–604
4. Peterson, G. E., Harary, F., Foundations in phonemic theory. In: R. Jakobson (Ed.), Structure of language and its mathematical aspects. Providence 1961. S. 139–165, wo Distanzfunktionen vorgeschlagen werden.
5. J. H. Greenberg, A quantitative approach to the morphological typology of languages. UAL 26, 1960, 178–194.