A.D.Rudnev. Materials on East Mongolia dialects. St.-Petersburg, 1911 (in Russian).
Andrey Dmitrievich Rudnev was one of the best mongolists at the beginning of the 20th century.
He was the teacher of B.Vladimircov and Y.Roerich.
His book became the first scientific description of North Mongolian dialects with comparative morphology and phonetics.