T. S. Willan, The Early History of the Russia Company, 1956, reprinted in 1968.
Jürgen Klein, "'Eastward Ho! Hakluyt's Principal Navigations on English 16th Century Seafarers in the Baltic and Eastern Europe", in: Zeitsprünge. Forschungen zur Frühen Neuzeit 10 (2006), Heft 3 - 4, pp. 400 - 423.