Unternehmen Seelöwe
In an afterword, Baxter described his influences as Niall Ferguson's book "Virtual History" (1997), Panzer General Heinz Guderian himself (from his book "Panzer Leader" (1952), Derek Robinson's "Invasion 1940" (2005), and Martin Marix Evans' "Invasion! Operation Sea Lion" 1940 (2005).