Brian W. Aldiss
4 appearances across 4 restored issues — every one readable in full, free.
Authentic Science Fiction Monthly, No. 82 — 1957 “What Triumphs?” (novelette) · p.4 Read the full issue (130 pages) → 
Authentic Science Fiction Monthly No. 83 — 1957 “OUT-OF-REACH” · p.78 Read the full issue (130 pages) → 
Amazing Stories, February 1968 — 1968 “LONDON LETTER” (feature) · p.143 Read the full issue (148 pages) → 
Amazing Stories, July 1968 — 1968 “LONDON AND OSLO LETTER” (article) · p.133 Read the full issue (148 pages) → Appearances are extracted from each issue's own printed contents page; entries we can't read confidently are withheld rather than guessed.