Cumbric

www.omniglot.com/writing/cumbric.htm - Information on Cumbric, and the constructed language Cumbraek based off it.

omniglot.com/language/numbers/celtic2.htm - Traditional ways of counting sheep in parts of north England, thought to be a remnant from Cumbric or some other Brithonic language.

en.wikipedia.org/wiki/Yan_tan_tethera - More on the traditional ways of sheep-counting.