21 books • 3 series
Book #3: Triumph 1913-1926, Model LW (Junior, Baby)
Book #4: Triumph 1915-1924, Model H and TT Roadster Model D
Book #5: Triumph 1920-1927, Model SD (plus German Modell T and T II)
Book #9: Triumph 1925-1927, Models P, Q and QA-1
Book #10: Triumph 1927-1928, Models N, NP and QA-2
Book #566: Beyond the J Curve