Read this: It should be noted that Estonian words and names quoted in international publications from Soviet sources are often back-transliterations from the Russian transliteration. Examples are the use of "ya" for "ä" (e.g. Pyarnu instead of Pärnu), "y" instead of "õ" (e.g., Pylva instead of Põlva) and "yu" instead of "ü" (e.g., Pyussi instead of Püssi). Even in the Encyclopædia Britannica one can find "ostrov Khiuma", where "ostrov" means "island" in Russian and "Khiuma" is back-transliteration from Russian instead of "Hiiumaa" (Hiiumaa > Хийума(а) > Khiuma).

What is the Russian back-transliteration from Encyclopædia Britannica?
What is the answer? (If it cannot be answered, return "unanswerable")
"ostrov Khiuma"