- Although this character was originally introduced during DC's Earth-One era of publication, their existence following the events of the 1985–86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and should be considered apocryphal.
- 10 Appearances of Harold Knopf (New Earth)
- 1 Images featuring Harold Knopf (New Earth)
- Quotations by or about Harold Knopf (New Earth)
- Character Gallery: Harold Knopf (New Earth)
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