This article is from the Mongolia FAQ, by Oliver Corff with numerous contributions by others.
Buryatia can be reached via Russia. The country code is ++7 but there
are two city codes for Ulan Ude: 3012 for 6-digit telephone numbers,
30122 for 5-digit telephone numbers.
Kalmykia is also reached via Russia, its area code is 847 and a
district Code may appear between it and your local numbers.
 
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