Heinkel He 112: (Schiffer Military/Aviation History): Hans-Peter Dabrowski, This little known Heinkel fighter design was eventually canceled yet saw service in the Spanish Civil War.: 9780764303920: Amazon.com: Books
Why was the Heinkel all-metal monoplane fighter plane dropped in World War II, despite its phenomenal range (715 miles) and numerous other merits? - Quora
Heinkel He 112 in Action - Aircraft No. 159: Denes Bernad, Joe Sewell, Randle Toepfer, Don Greer: 9780897473521: Amazon.com: Books
File:Heinkel He 112 (15083319030).jpg - Wikimedia Commons
112 png images | PNGEgg
German Warplane survivors, 1939-1945: Heinkel
Heinkel HE 112 B0/B1, Modelex 240 (201x)
When The Luftwaffe Stuck Two Bombers Together | Heinkel He-111 Zwilling - YouTube