Dicks, Terrance. Changing Universe: SS World
Divergence: 1940 CE
What if: The British Expeditionary Force surrendered to the Germans at Dunkirk.
Summary: British teenagers are trapped in a 2015 where Nazi Germany rules Europe, India and parts of Africa.
Comments: This is first in a series of novels featuring teenagers cast into alternative worlds by a malfunctioning teleporter. Other titles include Ecocrash and Mars Project, which may or may note be allohistorical.
Published: Piccadilly 1998 (1853405310, 1853405361).