The archives of the London Magazine are held, along with so many other amazing archives, at the Ransom Center at the University of Texas at Austin . Sylvia Plath had her poems, stories and other prose published in the London Magazine from June 1958 ("Spinster" and "Black Rook in Rainy Weather") through January 1963 ("The Applicant" and "Stopped Dead") in her lifetime and also made appearances after her death, from April 1963 and beyond. Plath dealt with a few people on the staff of the magazine over the years, including John Lehmann, Charles Osborne, and Alan Ross. In addition to what was found at the University of Texas, I would be remiss if I did not mention that the Mortimer Rare Book Room of Smith College has photocopies of a number of Plath's letters to Lehmann and Osborne. These are contained in the Edward Butscher papers . Presumably the originals of these letters are with the London Magazine records in Texas, but as I have seen ...
Sylvia Plath Info Blog by Peter K. Steinberg. The blog of A celebration, this is.