Island Mentalities – Research blog by Harry Wood
Riddle of the Sands – Catalogue of Victorian and Edwardian invasion, future war and spy literature run by Derek Linney
Archive.org – Includes wide range of digitised invasion-scare novels
Airminded – Airpower and British Society 1908-41, research blog by Brett Holman
Derek Linney has very kindly given us access to his Invasion Fiction source databases in PDF and Excel format. These list invasion texts published between 1851 – 1914 and are searchable in terms of invaded nation, invaders, allies and technologies.