German bomber production 1936-1940

[Birgir Thorisson]

I have many books about german aircraft and Luftwaffe, but have been unable to extricate detailed production figures from them. Is there anywhere on the net available monthly production figures for the major bomber types (Do 17, He 111, Ju 86 and 88). One book, (Dressel/Griehl, "The Luftwaffe album".p.36), claims that of 787 He 111 in Luftwaffe service on sept. 2 1939, approximately 400 were He 111 H-1 and H-2 which had been produced in mere four months! Is that credible?

Thanks in advance for information.

Birgir Thorisson