"Submarine Warfare In The Civil War," Mark Ragan, De Capo Press (Perseus Books Group), (Cambridge, 2002).

"The Story of the Submarine: From the Earliest Ages to the Present Day," Lieut.-Col. Field and Brevet Col. Cyril, (J.B. Lippincott Company, Philadelphia, 1905).

"The Submarine Pioneers," Richard, Compton-Hall, (Sutton Publishing, 1999).

"Submarine Navigation: Past and Present, Allen Burgoyne, (E. P. Dutton & Co., New York, 1903).

"The 'Mad Bavarian' Built Germany's first U-Boat in 1851, but his greatest Challenge was to find a Navy that was Interested", Tom Todd, (Weaponry, Military History Magazine (October, 1998), Pages 12, 16, & 18).