I am writing an essay about the old english ballad "The Unquiet Grave" and find in the essay I am writing a quotation that I apparently quoted with - unusual for me - no attribution: "Mine is an unquiet grave ... pulsing with ignorant livelings overhead ..."
I do not remember where I read that.
I have searched extensively including the following: Google; Google Scholar; Google Books; Internet Archive; HathiTrust; WikiQuote; The Quotations Page; Quote Investigator; my entire macbook pro laptop for text phrase with the search engine FindAnyFile.
Thanks for any help!