ŻEBRO in Polish (yes, we just have to add a hushing, buzzing or hissing sounds everywhere). :)
See, every linguist will tell you R is ancient. So Polish version is later addition. That is even obvious. Serbs live southern, in area where people lived during Ice age. After Ice age people migrated along the rivers up north.
Take this. Serbs says VEVERICA (Squirrel) and Russians say BIELKA. Older is VEVERICA. Why? Linguists say because naming of animals by the color coming when people migrate from one area where animal live and then come in a new region and encounter same animal. From warmer to colder climate. When spot same animal in white color people will name it BIELKA and then forget VEVERICA. Its never vice versa.
And did Serbs build Stonehenge, ...?
Its not impossible. If during Ice age Europe was Balkan and ethos Serb was formed its not hard to imagine that after Ice age, when people migrated up north, name was spread allover Europe. And we really finds that name all over Europe. And primarily along line Balkan-Baltic along the Danube river.
If so, then all Whites are ethnic Serbs. At least in origin.