Other interesting books in a similar vein ;
German Aircraft of the First World War, Thetford. Superb record of all German types, hampered only by relatively small page size;
British Aeroplanes 1914-18 , J M Bruce. Definitive collection of all British types, 740 odd pages. Included interesting analysis of every type.
French Aircraft of the First World War, Davilla & Soltan. 600+ quality pages! including fold-out plans, for when WNW get around to Nieuports & SPADs.
Italian Aces of WWI & their Aircraft, Gentilli. The definitive Italian analysis, 600 glossy, lovely pages.
The Imperial Russian Air Service, Durkata. Massive, glossy, colourful, epic. The definitive work on the subject, even if most types are French.
That lot will give you a good, broad, high quality, in depth library of pretty much every type of WWI aircraft, save the Curtiss Jenny perhaps! But it will be expensive, so watch EBay. They do come up occasionally at reasonable money.