Harold Biondo

Ministry of Supply, Extracts of A.F.V. Division Letter No. 5

(WDGS Report R3154-45) D.T.D. No. 30 - Appendix "A" to Preliminary Notes on German 15 cm s.F.H. 18/m on S.F.L. IV "Hummel"

WDGS Report R230-45 - Hummel

ETO Ordnance Technical Intelligence Report No. 385 - German Self-Propelled Gun Chassis as Cargo Carrier

CIOS Report XXIX-22 - History of German Tank Development

CIOS Report XXVII-47 - Interrogation of Dr. Stiele von Heydekampf President of the Panzer Kommission

Iguanicus-Rex's Documents Part 2.5 - Comparison of German and American Weapons

School of Tank Technology, D.T.D. No. 3057 - Preliminary Notes on German 15 cm. s.F.H. 18m on Sfl.IV "Hummel"