Not directly OSR related, but this is the literature that inspired the game. On issue of Planet Stories and 3 issues of Avon Readers, which basically just took old pulp stories and reprinted them, sans illustration or ads.
Planet Stories v2 08 - Most notably has a sword & planet tale from Henry Kuttner, The Eyes of Thar
Avon Fantasy Reader 15 -Has a sword & planet adventure from Stanley Weinbaum (and a heck of a cover), a story about a guy with ape servants and some other stuff.
Avon Fantasy Reader 17 - Featuring (and the cover) The Sapphire Siren. It's funny, while 1950s male heroes went shirtless, they still pulled their pants up to their navel and some older tales by HPL and William Hope Hodgeson
Avon Science Fiction Reader 1 - This has a cover like from a Venger Satainis module, but is actually for a story from Edmond Hamilton, and has stories from A. Merritt, CAS, Frank Belknap Long, and Donald Wollheim.