Col. Robert J. Icks was a trailblazer in the field of tank and armored vehicle history. He co-authored one of the very first books published on the topic in 1933, The Fighting Tanks 1916-1933. His book Tanks & Armored Vehicles 1900-1945, published at the end of WW2 is one of the true classics of the period. Later he would write several entries in the Armour in Profile series and AFV Weapons Profile series.
Portrait Of Power: A Photo-History Of United States Tanks And Self-Propelled Artillery