I have the same problem, I have 'Brisk Russian' on the right hand side of the 1911 English Census on mine and also cannot find how they got to England. Some went to different places before settling, so it's worth looking in a few directions. Some of my Ancestors split and went to different countries, the USA were very good at documenting.
Good luck, if you find anything let us/me know !
Researching Brest, Belarus, Hungary, Galacia