The CRAMLAP logo has been inspired by the ‘wave hypothesis model’ of language inter-relationships. This was introduced in 1872 by Johannes Schmidt to represent the distribution of Indo-European languages and illustrate how population groups in contact can influence each others linguistically.

Der Verwandtschaftsverhaltnisse diagram
This was reformulated by Lehmann in 1962 as below:

Lehmann,: Historical Linguistics
CRAMLAP has adapted Lehmann’s Venn diagram to the Celtic triskell which can also reflect relationships within linguistic diversity.
Lehmann W. P., 1962, Historical Linguistics, an Introduction, New York, Holt, Rinehart & Winston.
Schmidt J., 1872, Die Verwandtschaftsverhältnisse der indogermanischen Sprachen, Weimar, Böhlau.