LEMB-Luftwaffe Experten Message Board (http://p069.ezboard.com/bluftwaffeexperten71774): superb BBS on Luftwaffe topics.
LuftArchiv.de (http://www.luftarchiv.de/): Astounding site on the Luftwaffe of World War 2
Tarrif.net (http://www.tarrif.net/): Supurb site on general info World War 2 hardware.
WWII Tech Pubs (http://www.wwiitechpubs.info/): Excellent but limited site on World War 2 hardware.
Gustin's Military Aircraft Database (http://www.csd.uwo.ca/~pettypi/elevon/gustin_military)
The Luftwaffe, 1933-45 (http://www.ww2.dk/): Who, what, where, when! Simply the ultimate reference site!
Do-215 D(Luft)T 318/2, Handbuch. Berlin: 1940
Do-17z Flugzeug-Handbuch. Berlin: 1940
Do-17z Waffen-Kompendium, gesamt L.DV. 584/5, 585/9, 585/10, 584/5a . Berlin: 1940
Do-17P Airplane Handbook L. Dv. 553/4 (entwurf). Berlin: Siegfried Rittler und Sohn(?), 1940
Do-17z Bewaffnung und Bildgerat Zur L.DV. 584/5. Berlin: 1940
Do-17z-7 Bedienung der starren Schutzwaffe D. T. 2131/4. October 1940 (no city or publisher, noted with "Only for offical use")
Nowarra, Heinz J. "Dornier-Bomber". Der Landser-Grossband; Germany, Dec. 1991.
Dornier Products Brochure. Dornier-Werk, 1938?
"Annals of the 'Pencil', Story of the First-Generation Do-17", Air Enthusiast/Thrity, 1981, Pages 38-53.
Smith, Richard J. Profile 164, Dornier Do17 & 215 . Berkshire: Profile Publications, Ltd., 1971.
Nowarra, Heinz J. The Flying Pencil, Dornier Do17 and Do215. Pennsylvania: Schiffer Publishing, 1990.
Green, William. War Planes of WWII, Bombers and Reconnaissance Aircraft, Vol. 8 . London: Macdonald, 1967.
Green, William. War Planes of WWII, Fighters, Vol. 1 . London: Macdonald, 1960.
"Dornier's Flying Pencils." The Illustrated Encyclopedia of Aircraft, Vol. 14 #161 . 1984: 3205-3211
Price, Alfred. German Air Force Bombers of WW2, Vol. 1. New York: Doubleday, 1968.
Price, Alfred. German Air Force Bombers of WW2, Vol. 2. New York: Doubleday, 1971.
Price, Alfred. The Luftwaffe in Camera, 1939-1942. Gloucestershire: Sutton, 1997.
Toll, Karl. "The Lufthansa Bomber." AIRPOWER , Vol. 3, #1. Jan. 1973: 36-51.
Filley, Brian. Junkers Ju 88 in Action, Part 2 . Carrollton: Squadron/Signal, 1991.
Gunston, Bill. An Illustrated Guide to Bombers of WW2. London: Salamander Books, 1980.