Strabo, Geography
H.C. Hamilton, Esq., W. Falconer, M.A., Ed.

Hyrcania is watered by the rivers Ochus and Oxus as far as their entrance into the sea. The Ochus flows through Nesæa, but some writers say that the Ochus empties itself into the Oxus.

Aristobulus avers that the Oxus was the largest river, except those in India, which he had seen in Asia. He says also that it is navigable with ease, (this circumstance both Aristobulus and Eratosthenes borrow from Patrocles,) and that large quantities of Indian merchandise are conveyed by it to the Hyrcanian Sea, and are transferred from thence into Albania by the Cyrus, and through the adjoining countries to the Euxine. The Ochus is not often mentioned by the ancients, but Apollodorus, the author of the Parthica, frequently mentions it, [and describes it] as flowing very near the Parthians.