Words that come from Proto-Indo-European ḱer(s)-

5 words across 4 languages descend from Proto-Indo-European ḱer(s)- — including шерсть, sierść, sьrstь, сьрсть, шьрсть.

See the etymology of ḱer(s)- itself →

Old East Slavic (2)

Russian (1)

Polish (1)

Proto-Slavic (1)