Pg. 73 of David Markson’s copy of The Essential Shakespeare: A Biographical Adventure by J. Dover Wilson:

     On which Markson has written “Wm. W” next to the quote:
     “Mighty poets in their misery dead.”

—

     “Wm. W.” = William Wordsworth

     Who, in the poem Resolution and Independence, wrote:
     “My former thoughts returned: the fear that kills;
     And hope that is unwilling to be fed;
     Cold, pain, and labour, and all fleshly ills;
     And mighty Poets in their misery dead.
     —Perplexed, and longing to be comforted,
     My question eagerly did I renew,
     ‘How is it that you live, and what is it you do?’”
     (Italics mine.)

     On pg. 159 of his novel This Is Not A Novel, Markson wrote:
     “And mighty poets in their misery dead.”
     (Italics Markson’s.)