We solved the clue 'He wrote “All that we see or seem / Is but a dream within a dream”' which last appeared on November 23, 2019 in a N.Y.T crossword puzzle and had zero letters. The zero solution we have is shown below. Similar clues are also included in case you ended up here searching only a part of the clue text.
HE WROTE ALL THAT WE SEE OR SEEM IS BUT A DREAM WITHIN A DREAM