Vasiliev.Astronomical observations and chronometric comparisons in the Fortress of the Belorogolovskaya.

Vasiliev.Astronomical observations and chronometric comparisons in the Fortress of the Belorogolovskaya.- 1838. -Agreement No. 24 of 02/12/2016 category 26 of the manuscript of the works of members of the Russian Geographical Society and separate documents on the Orenburg province, case 5..Electronic copy source: PB