Convert from vershok to bicron

Unit Definition (vershok)
Obsolete Russian weights and measures were used in Imperial Russia and after the Russian Revolution until they were replaced in the Soviet Union by a metric system in 1924.

Unit Definition (bicron)
The Bicron is an obsolete metric unit of distance, which was defined as 10e-12 meter or 10e-6 micron. This distance is now called a picometer or picometre (pm). The name is a reference to the double prefix "micro-micron".