This map of the city of Astrakhan' was produced by Samuel Gottlieb Gmelin and was included in the second volume (1774) of his work "Reise durch Russland zur Untersuchung der drei Natur-Reiche."
This edition of John Bell's "Travels..." was printed in two volumes detailing Bell's travels from 1715 through 1718 along the Volga River, the Caspian Sea and into Persia.
This 4 volume work by Jonas Hanway details much of the economic activity enriching the Russian Empire along the edges of the Caspian Sea in the 1740s and 50s.