It is quite common to find texts on Pickelhaube relating to the First World War, but it is more difficult to find volumes predating this conflict. Apart from the titles from Verlag Militaria (which also includes a beautiful double volume on the Franco-Prussian War), the works of J. K. Kube, and the various catalogues, including Hermann Historica, I have difficulty finding the perfect book that also examines the less celebrated headgear, such as the Bavarian Landwehr examples or all types of Raupenhelm, and Saxon army, with particular reference to those from the mid-1800s. It is even more difficult to find texts on Russian Pickel [helmets], which I adore since I have one in my collection. If you are interested, I have some well-written articles on the latter. The same thing for Austrian army, For example, about the evolution of the notorious dragoon helmet.
Aside from what I have mentioned, do you have any other reference texts?
Aside from what I have mentioned, do you have any other reference texts?