Leonid L. Kasatkin. Akanye and jakanye in one old believers dialects and the historical issues of these vocalism systems
RJANO. 2013. № 1 (25), Pages. 70 - 85

Leonid L. Kasatkin. Из истории аканья — яканья в русском языке
RJANO. 2010. № 2 (20), Pages. 77 - 102