LC authorities (en ligne), 2009-02-18
Reflections on the menaced invasion and the means of protecting the capital, by preventing
the enemy from landing in any part contiguous to it : a letter to the Earl of Harrington,
on the proposed fortifications round London. A defence of the volunteer system, and
the means of employing it to the greatest advantage. And a correct military description
of Essex and Kent, with the military roads and strong positions in those counties
/ by Colonel George Hanger, 1970