Abraham Socher's article which was originally published in the Times Literary Supplement (TLS), July 1, 2005. It is easily available at Zembla, where it's been reprinted and with two paragraphs restored, plus other minor additions.  shades of frost: a hidden source for nabokov's pale fire  libraries.psu.edu/nabokov/socher.htm - 

 

a sample excerpted from Abraham Socher's article: "Andrew Field...asked the author about the connection between John Shade, the fictional poet of Pale Fire, and Robert Frost...Field was right to wonder. Nabokov gave two poetry readings with Robert Frost, in 1942 and 1945, and was, along with Frost, Archibald Macleish and T. S. Eliot, one of four speakers who appeared in Wellesley College's "Poets Reading" series in 1946....Seven years later, in 1952, Nabokov and his wife even briefly rented Frost's house in Cambridge, Massachusetts. They found it too cold to stay in, but amusing to later pun about ("the Jack Frost house")...Field had grounds for suspecting that the relationship between John Shade and Robert Frost was more than superficial, but he did not pursue them very far[ ...]  Michael Wood writes: "Shade resembles Frost a little: in looks; slow, sly style of wit...He is a milder character than Frost though; kinder and a lot more than a footstep behind him as a poet." ... Wood does make a more substantive comparison between Frost and Shade a little later. In the fourth canto, John Shade detects...signs of artistic design in the arrangements of his universe...Wood finds this aesthetic theodicy, which Nabokov certainly shared with Shade, profoundly unappealing, and compares it to Frost's famous sonnet of a spider and its prey: 'Shade is several footsteps behind Frost here.' ...Wood's comparison is unduly harsh...In his commentary, Kinbote adduces Frost's "Stopping by Woods on a Snowy Evening"...Is there another "short poem" concealed behind Kinbote's misdirection? If there is, it might also reveal something of the improvised methods and secret stratagems by which Nabokov managed to enter, appropriate, and even command the poetic tradition to which Frost was heir, in which his Russian sceptre was powerless...Nineteen sixty-two, when Pale Fire was published, was also the year that Frost published In the Clearing, his final book...Frost had unknowingly helped to erase the paper trail to the poem whose reflected light shines from the opening lines of "Pale Fire," and without which Nabokov's novel is almost unimaginable."