KEY TO CATEGORIES

P = Prototypes/Precursors
A = Paradigms
B = U.S. Futuristic Stories and Adventure Stories (1800-1926)
C = British Futuristic and Adventure Stories (1800-80s)
D = British Scientific Romance (1880s-1950)
E = U.S. Genre (1926- )
F = U.S. Mainstream (1926- )                
G = British (including Commonwealth) Genre (1945- )                
H = British (including Commonwealth) Mainstream (1945 - )